Ch ngha x hi i v u?Joseph E. Stiglitz

Nguyn Quang A dch

Tn sch: ntNgun: internetChnh t: capthoivu (TVE)Chuyn sang ebook: capthoivu (TVE)Ngy hon thnh: 4/9/2006Ni hon thnh: ASEC-JakLi gii thiu ca ngi dchLi ni u1. L thuyt v ch ngha x hi v

quyn lc ca cc t tng kinh t2. Tranh lun v ch ngha x hi th

trng: Cch tip cn c bn3. Ph phn nh l c bn th nht

ca kinh t hc phc li4. Ph phn nh l c bn th hai5. Ph phn nh l Lange-Lerner-

Taylor: Cc khuyn khch6. Phn phi khu phn ca th

trng v nhng phn b phi gi ctrong ni b cc nn kinh t th trng

7. Cnh tranh [3]8. i mi (Inovation)9. Tp trung ho, phi tp trung ho,

cc th trng v ch ngha x hi thtrng

10. T nhn ho [1]11. Th nghim X hi ch ngha:

sai ci g?12. Ci cch cc th trng vn [1]

13. t cc cu hi ng: L thuytv bng chng [1]

14. Nm huyn thoi v th trngv ch ngha x hi th trng

15. Vi kin ngh s b16. Nhng suy ngm trit hc17. Nhng kt lunTi liu tham khoCc Bi ging WicksellNm 1958 Hi Bi ging Wicksell

[The Wicksell Lecture Society], vi shp tc ca Vin Khoa hc X hi thuci hc Stockholm [the Social ScienceInstitute of Stockhol University], TrngKinh t hc Stockholm [the StockholmSchool of Economics], v Hi Kinh tThu in [Swedish EconomicAssociation], khai trng lot cc biging tn vinh v tng nh Knut

Wicksell (1851-1926). n 1975 cc biging c trnh by hng nm. Sau mtthi k tm dng lot bi ging li cHi Kinh t Thu in khai trng linm 1979. Bt u vi cc bi ging1982, mt tp cc bi ging c trnhby hai nm mt.

Li gii thiu cangi dch

Quyn sch ny l quyn th 6 ca tsch SOS2 do chng ti chn v dch rating Vit. N c Joseph Stiglitz vithn mi nm trc, vo nhng nm uca thi k chuyn i, v c xut bnu tin nm 1994. ng l ngi c cngchnh trong pht trin kinh t hc thng tin,v v nhng cng hin ng c giiNobel kinh t nm 2001. Trong cun schny ng dng nhng kt qu nghin cuca mnh v ca cc cng s v kinh thc thng tin lm r hn nhng vn tranh lun lu i v cc m hnh kinh t,cc h thng kinh t, v trn c s a

ra nhng gi chnh sch cho cc nn kinht chuyn i hu x hi ch ngha.

ng ph phn cc l thuyt kinh t tnc in, m hnh x hi ch ngha thtrng v m hnh th trng cnh tranhtruyn thng da trn l thuyt , lm rhn nhng im mnh im yu ca cc hthng kinh t. ng gi nhng chnh schkinh t cho cc nn kinh t chuyn i.

Ph phn v nh gi ca ng kh cnbng v khch quan trn c s nhng ktqu mi nht trong nghin cu kinh t. cgi ca t sch SOS2 s thy cun schny rt l th, nht l sau khi c cccun sch khc ca t sch, c bit l haicun u ca Kornai.

Joseph Stiglitz tng l c vn kinht ca tng thng Clinton, l Ph Ch tchNgn hng Th gii. ng thng xuyn

tho lun cc vn kinh t chuyn ivi cc hc gi v quan chc Trung Qucv cc nc ng u t u nhng nm1980, v cho cc nh hoch nh chnhsch nhng li khuyn b ch. Vit Nam bt u cng cuc chuyn i hn milm nm nay. T gia cc nm 1990, ng vi ln n Vit Nam; Chnh ph VitNam dng nh nh gi cao nhng likhuyn ca ng.

Vi cc c gi Vit Nam cun schvn c nhiu ngha su sc. N khngch mang n cho chng ta nhng suy ngmsu xa lin quan n ni dung cc cuctranh lun lu i v cc m hnh kinh t,nhng vn hc thut uyn thm, m cnmang tnh thi s nng hi cho cng cuci mi t nc. Trc ht n, cng nhcun H thng X hi ch ngha ca

Kornai, gip chng ta hiu r hn lch skinh t ca mnh trong hn na th k qua,hiu r hn nhng vn hin ti, v hivng gp phn quan trng trong nh racc bc i thch hp trc mt v ludi.

Cun sch khng ch b ch cho cchc gi, cc nh hoch nh chnh sch, mcng rt b ch cho cc nh doanh nghip,cc nh bo, sinh vin v nhng ngiquan tm khc.

Tuy bn lun v nhng vn l thuytsu xa, song cun sch khng dng nnhng kin thc ton hc cao siu, nn cth d c hn vi qung i bn c. Tuyvy, y l cun sch chuyn kho, cnphi c nhng hiu bit nht nh mi cth hiu c. C mt vi thut ng ton(kinh t) c th l tai i vi mt s bn

c (th d nh tnh li [convexity], tnhkhng li [nonconvexity], tuyn tnh[linearity], phi tuyn [nonlinearity], v.v)bn c nn xem li cc khi nim ton scp hay cao cp lin quan. C mt vithut ng kinh t, nh rent [tin thu, t]i khi c dch nht qun l c licho ph hp vi rents seeking [tm kimc li]; hoc polyarchy [(a?) th bc]li c dng nht qun l phi th bc i lp vi hiearchy [h thng th bc], cth gy kh chu cho mt s c gi. Ttc nhng im nh vy u c nh dusao (*) cc ch thch hp. Mi ch thchnh s u l ca tc gi, cc ch thchnh du sao (*) l ca ngi dch. trnh nhng kh khn trn, v gip vicnghin cu c thun tin phn ch mc[index] t m v cc khi nim, dn chiu

chng ti km c thut ng ting Anh tin dng.

Do hiu bit c hn ca ngi dch,bn dch chc cn nhiu sai st, mong bnc lng th v ch bo. Mi gp xingi v Tp ch Tin Hc v i Sng25/B17 Hong Ngc Phch [Nam ThnhCng] H Ni, thds@hn.vnn.vn, hocnqa@netnam.vn.

H ni 11-2003

Nguyn Quang A

Li ni uQuyn sch ny m rng cc bi ging

Wicksel m ti trnh by TrngKinh t hc Stockhom thng t 1990. Khiu ti d nh trnh by mt tng quan vhin trng ca kinh t hc thng tin, tiuim ca phn ln nghin cu ca ti suthai thp k qua. Nhng nhng s kin ng u - s sp ca ch ngha x hivi tc hon ton bt ng - a ranhng vn chnh sch mi v khi licc vn l thuyt c: Chuyn i sangmt nn kinh t th trng b tc ng rasao? Nhng kinh nghim ny c ngha gvi cuc tranh lun ko di lin quan ns la chn cc h thng kinh t kh d?

Nhng vn ny lin quan n mt

vn th ba: cc m hnh kinh t truynthng c ngha g vi nhng vn kinht cn bn nh vy? Kt lun m ti rt ravt qu s ph phn rng cc m hnhchun chng c my ngha i vi ccvn ny. Vi ti dng nh l, cc mhnh chun c li mt phn cho tnh trngtai hi m nhiu nc ng u lmvo. Trong mt on thng c trchdn, Keynes vit:

Cc tng ca cc nh kinh t v cacc trit gia chnh tr, c khi h ng lnkhi h sai, c quyn lc hn l ngi tathng vn tng. Thc vy, th giic cai tr bi my ai khc. Nhng ngithc tin, tin rng mnh khng b bt k nhhng tr tu no, thng l n l ca nhkinh t hc cht no . Nhng k mttr c quyn lc, nghe nhng li ni vin

vng, ang cht lc s in cung ca ht hc gi bt ti no y ca my nm qua. Ti chc chn rng quyn lc canhng gii c th lc tng qu mc sovi xm ln dn dn ca cc tng.

C th bin h mnh m cho nh rng cc tng v kinh t hc dn gnmt na dn s th gii n au kh khngk xit.

Kinh t hc tn c in thng t chomnh l i lp vi kinh t hc ca Marx.Nhng kinh t hc tn c in, t nht dng quen thuc trong cng ng Anh-M,thc t khng cung cp mt la chnkh d c th ng vng. N cung cp mtm hnh v nn kinh t dng nh qu xanhng lc lng c bn to s ng h chokinh t hc ca Marx trong nhng githuyt, nhng m t, v nhng mi quan

tm ca n. Bng cch lp lun rngdng nh chng ta l tt nht trong mith gii kh d, chng khng nh mt cchtho ng g i vi nhu cu ca nhngngi thy s khn kh kinh t khp ni.Ti hn na, trong khi ch ra sc mnh cacc th trng, n dng nh lp lunrng ch ngha x hi c th hot ngc: Ch ngha x hi th trng c ths dng cc th trng, m nn kinh t vnkhng c nhng c im ti nht ca chngha t bn.

Kt lun ny sai l iu dng nh rrng hin nay. Nhng v sao n sai ling l bi hc. N ni cho chng ta ci g v c nn kinh t ln cc m hnh mchng ta dng nghin cu ch nghat bn. Mt mc tiu chnh ca cc biging ny l k li cu chuyn y.

S khng ngc nhin i vi nhngngi theo di cng trnh ca ti, rngti coi thiu st ct li trong m hnh tnc in l cc gi thit ca n lin quann thng tin. Trong cc cng trnh trcy ca ti v kinh t hc thng tin, ti ch ra rng nhng s xo ng nh trongcc gi thit chun v thng tin lm thayi mnh m tt c cc kt qu ch yu cal thuyt chun tn c in: L thuyt honton khng vng cht no.

Ti hi vng rng cc bi ging nyvt qu vic ch bai, nay thnh quenthuc, i vi m hnh chun, ch raxem h thuyt (paradigm) l thuyt thngtin mi c th mang li nhng ci nhn mith no trong cc vn l thuyt v nnkinh t vn hnh ra sao - th d, vai tr cacnh tranh v phn quyn [phi tp trung

ho] - v trong vic a ra cc chnh schcho cc vn thc tin m cc nn kinht chuyn i phi i mt. Tuy vy tiphi nhn mnh rng, trong khi cc githit v thng tin lm c s cho l thuytchun c l chnh l im yu ct t, l gtAchilles, ca l thuyt, n chng vt quim : Cc gi thit lin quan n tnhy , n tnh cnh tranh ca cc thtrng, v s thiu vng ca i mi sngto [trong l thuyt chun] l ba [thiu st]m ti nhn mnh.

Xy dng mt h thuyt mi l mtqu trnh chm. Ci m ti gi l l thuytchun c trau chut lin tc qua ccnm. L thuyt by gi c th c phtbiu vi tnh tng qut ton hc cao.Nhng tnh tng qut cao hn khnggip g cho tnh tho ng ca l thuyt.

Vn liu l thuyt c s c bt k ngha no i vi nn kinh t ca chng tachng h da vo tnh kh vi [1] ca cchm s lin quan. Qu nhiu ngun lc cagii chng ta c dnh cho vic trauchut mt m hnh c qu t ngha vinn kinh t, ng rng c mt s phi hiuqu trn th trng v cc tng, ci tnht cng ln nh s phi hiu qu cc thtrng vn v lao ng.

Cc m hnh ton hc hnh thc nmbt mt s kha cnh ca cc tng ctrnh by cc trang tip theo - th d, vaitr ca cnh tranh trong cung cp thng tin,vai tr ca phn quyn trong cc t chcni mi c nhn c thng tin hn ch, hocvai tr ca chnh ph can thip vo ccnn kinh t vi cc th trng khng honho v thng tin khng hon ho - c

pht trin. Nhng y ti khng c nh im li hoc m rng cc m hnh: Cc c gi quan tm c th xem ccti liu tham kho. Thay vo , theo tinhim v ca mt lot bi ging nh lotbi ging ny l a nhm cc tngvo ng vin cnh ca n. Nu ti thnhcng trong vic to ra nhng nghi ng vh thuyt ang thnh hnh, nu ti thuytphc c c gi rng c mt h thuytla chn kh d ng theo ui, v nu, vl do , m c mt s ti phn b nhnhoi cc ngun lc tr tu ca gii chngta, th ti t mc tiu ca mnh. Nucc bi ging t ra c ch cho nhng ngi trong qu trnh chuyn i, nu khngphi trong vic a ra cc cu tr li, tht nht trong vic gip to ra khun khcho tho lun, th ti cng hi lng hn.

Ti mang n su nng i vi cc sinhvin, cc ng nghip, v c bit vi ccng tc gi ca ti, nhng ngi m ti cng tho lun nhiu tng trong cunsch ny sut hai thp k qua. Nhng nhhng ca Richard Arnott, AviBraverman, Partha Dasgupta, BruceGreenwald, Michael Rothschild, BarryNalebuff, Steve Salop, David Sappington,Carl Shapiro, v Andrew Weiss l cbit r rt. Joshua Gans v Michael Smart tr gip nghin cu. Nhng bnh lunsu sc ca h ci thin bn tho cuicng rt nhiu. Jean Koentop v LindaHandelman thc hin cng vic th kthng l tuyt vi ca h, bin tp bntho khi nh my.

Ti cng c li t nhiu bnh lunca cc ng nghip tham d cc bi

ging Stockholm v cc seminar Budapest, Praha, v Roma nhng nicc phin bn ca nhiu chng ctrnh by. S quan tm ca ti n cc vn ca ch ngha x hi bt u t nhngngy cn l sinh vin sau i hc, khi tin Trng Thng k Trung ng Warsaw ni chuyn vi Lange, Kaleckiv cc mn ca h. Ti thu c nhiuhiu bit su sc v l thuyt v thc tinca ch ngha x hi, v rt cm kchtrc lng mn khch ho hip ca h. Squan tm ca ti v cc vn chuyn iu tin c gi ln nm 1981, ti mtcuc gp mt c ti tr bi Vin hnlm Khoa hc Quc gia [NationalAcademy of Science] v Vin hn lmKhoa hc X hi Trung Quc [ChineseAcademy of Social Science]

Wingspreads, Wisconsin ( ti trnhby mt phin bn ban u ca mt trongcc chng ca cun sch ny), v mtcuc ving thm p li Bc Kinh voma h tip theo. T khi , ti c maymn tin hnh nhiu cuc ving thm tiHungary, Tip Khc, Rumani, v TrungQuc, nhng ti khng th cho rng mnhl mt chuyn gia, trn c s nhng cinhn thong qua ny, v hng lot cc vn m cc nc ny i mt. Ti hi vng,v tin, rng nhng thu hiu l thuyt c thc gi tr no y.

Ti cm n s tr gip ca nhiu tchc h tr ti chnh v to thun licho vic nghin cu nm ng sau cc biging ny: Qu ti tr Khoa hc Quc gia[National Science Foundation], Qu ti trSloan [Sloan Foundation], Vin Hoover

i hc Stanford, Chnh ph Rumani, VinCi cch Chnh sch [Institute for PolicyReform], B Ti chnh Cng ho Nhn dnTrung Hoa, v Ngn hng Th gii. Quantrng nht, ti mun cm n s h tr cai hc Stanford, to ra mt bu khngkh trong vic tho lun tch cc v cc tng cn bn nht c tin hnhmt cch ci m v si ni, trng choti cc ng nghip v cc sinh vin mhng ngy ti hc c rt nhiu t h.

1. L thuyt v chngha x hi vquyn lc ca cct tng kinh t

Trong th k ny chng ta n chhc c v quyn lc ca cc tngkinh t. Nhng quan im i ch v xhi phi c t chc ra sao ctranh ci khng ch trong cc phng tranhlun ca cc vin hn lm m c cc

chin trng Triu Tin, Vit Nam,Afghanistan, v Trung M. Chc chn,trong mi trng hp, vn khng nthun ch l cc tng kinh t. Cc dukch qun Vit Nam hoc Honduraschng quan tm n cc cuc tranh lun vl thuyt lao ng, v gi tr hoc cc giol khc ca kinh t hc ca Marx, ngay cnu h hiu r chng. Mc d vy nhngnim tin vo mt h thng kinh t kh d cth la chn, h thng ha hn mt cucsng tt p hn trong th gii ny, c nhhng n hnh ng ca h chng kmnhng nim tin vo cc h thng tn giokh d khc - ha hn s cu ri vnh hngtrong hu th - nh hng ti nhng ngi chin u d tn n vy trong cccuc chin tranh tn gio do hu qu caphong tro Ci cch [th k 16]. Nhng

nim tin b mt c m mnh bi ccs kin ng u trong vi nm qua, cbit vi s sp ca ca Chnh ph X-vit trong nm qua.

Nhng nu chng ta i tm thi imm ch ngha x hi khng cn c coi lmt la chn kh d so vi ch ngha tbn, th chng ta phi tm trc s giiphng ca cc nc ng u nm 1989.Bn cnh , s t chi ch ngha x hica h l mt s khng nh chnh tr, tchi mt h thng kinh t c k chimng p t ln h, cng nh l mt stuyn b v nhng tnh u vit ca h ttng . Ti ngh, chng ta phi ng licc cuc t nhn ho Php bt u vou cc nm 1980, c tin hnh bi mtchnh ph cng khai tha nhn l chnh phx hi (ch ngha), o ngc li hnh mu

quc hu ho m chnh ph tinhnh mi t nm trc. c nhng mch xa xi rng lng tin vo h t tng xhi ch ngha c th tan thnh my khitrong nhng nm trc : Th tng HyLp Andreas Papandreou, mt nh x hich ngha cng khai khc, coi "x hiho cc doanh nghip quc doanh" l mttrong nhng mc tiu ca chnh ph cang, cng nhn cng khai rng quan imc, rng quc hu ho mt doanh nghips m bo cho mc tiu ca doanh nghipy trng hp vi "li ch quc gia", btlun n c xc nh ra sao, chng cc s trong thc t, t nht trong bi cnhHy Lp. S sp ca ch ngha x hi,vi t cch l mt h t tng kinh t, lng ch nhiu mt cng nh s sp ng thi ca khi X-vit, biu trng

cho tt nh ca mt cuc th nghim kinht ko di na th k. l mt cuc thnghim c tin hnh vi suy tnh ngk, da trn c s ca mt h t tng tnti hn mt th k. H t tng ngu vi s xem xt k lng ca thi gian.Nhng ha hn v kt lun ca n ctranh lun rng ri, v trong hng ngnhng ngi ng h n bao gm mt sngi c tr tu nht sut thi k hn mttrm nm. Ngay c ngy nay nhng ttng v l tng Marxist to c s cho ht tng kinh t vn cn sng ng, khngch trong th gii th ba m c ccchuyn ngnh khc. Mt miu t y vnht qun v s ni ln, s bn b v ssp mt phn ca tp cc nim tin nyl rt hp dn nhng s dn ti i quphm vi ca cc bi ging ny. Nhng mt

lun m ti hi vng trnh by l, gintip hay khng ch , cc m hnh kinh ttn c in ng mt vai tr trung tmtrong truyn b v duy tr nim tin vo chngha x hi th trng - mt trong nhngbin th ch yu ca m hnh x hi chngha- nh mt la chn kh d thay choch ngha t bn. Ti lp lun trong ccbi ging ny rng, nu gi nh m hnhtn c in (hoc nhng tin thn ca n) cung cp mt m t ng ca nn kinht, th tht s ch ngha x hi th trng c c hi thnh cng. Nh vy s thtbi ca ch ngha x hi th trng a ramt s bc b m hnh tn c in chunht nh n bc b l tng x hi chngha th trng. Trong cc bi ging nyti c gng gii thch chnh xc hn ci gl sai vi m hnh v cung cp nhng

ni dung c bn ca mt h thuyt kh dkhc (alternative paradigm).

Theo hu ht nh gi, kt qu ca thnghim ch ngha x hi l khng mp m:Cuc th nghim l mt tht bi. Ging nhhu ht cc th nghim x hi n khngphi l mt th nghim c kim sot,nh th c s tranh ci v chnh xc phidn chiu n ci g - cc t tng c bn(nu khng phi l cc l tng) ca chngha x hi sai mc no v mc no tht bi c cho l do cch thchin cc t tng y gy ra, mc noc th vin dn nh do "cc tnh cht thitk c th"? [2]

i khi li cng c cho h thngchnh tr h khc i km vi th nghim xhi ch ngha: Ch ngha x hi th trngdn ch thc ra chng bao gi c th

nghim. Nhng mt bin h cng c thc a ra rng th nghim x hi thnh cng hn so vi trng hp khngc p bc Cng sn: bi v, mc nhtnh, h thng chnh tr p bc cung cpmt ci thay th - ci gy- cho s thiuvng ca c c rt ca nhng khuyn khchkinh t. C vn tng t liu c milin h nhn qu gia h thng chnh tr pbc v h thng kinh t x hi ch ngha.Nu khng phi l h qu khng th trnhkhi ca vic cho nh nc c quyntrong s hu t liu sn xut, th vn cth c "xu hng" tp trung quyn lc vomt lnh vc dn n s tp trung quynlc lnh vc khc.

Trong khi cc hc gi c th suy xt vcc ch ny, hu ht cc nc lin quandng nh quyt tm chuyn sang nn

kinh t th trng. H thy s thnh vngca cc nc Ty u, Bc M, v ng ,v h hi vng bng cch c vn ti nnkinh t , h cng s t c s thnhvng tng t. H i mt vi vn chuyn i kh khn - i th no t v trhm nay sang v th h mun tr thnh.Trong khi c s tin chc rng h munthnh qu ca mt nn kinh t th trng,c th khng c s tin chc nh th rngh mun c gi phi tr - s ngho khcng cc c trng cho hu ht cc nnkinh t th trng ngho hn, trong s cc nc ny chc chn phi c tnhn [3] - hoc l h sn lng chu chi phca chuyn i. Cui cng, cc nn kinh tth trng c tnh a dng v mu sc vsc thi. Cc nn kinh t x hi ch nghai mt vi mt tp cc vn kh khn

trong quyt nh loi hnh thc no hmun ly. Thc vy khng phi tt c ccnc nguyn x hi ch ngha cam kt y cho nn kinh t th trng. Mt s tholun v mt con ng th ba, nhngnhng ngi ph phn bc b n l khngth - nh ch thng c din t, bnkhng th c thai mt cht c.

i vi cc nh l thuyt kinh t ccvn i mt vi cc nn kinh t x hich ngha l nhng thch thc. ychng ta c mt nhm cc nc lao vola chn h thng kinh t. Hn l l thuytkinh t phi cung cp s ch o ng k.ng tic - t nht cho n gn y - khoahc kinh t chng c th ni my v nhngch cn bn ny, v thm ch cng thn v cc vn quan trng ca chuyni. Li khuyn in hnh ca nh t vn

ti thm v tin hnh chuyn i mt cchvi v cho mt nn kinh t i theo conng chuyn i l nhn mnh tm quantrng ca cc th trng, mt bi hcdng nh by gi c hc k (mcd nhng ngi ng h th trng s nirng l bi hc khng th nhc li qunhiu ln v, n gin nh n c v, mni dung ca n dng nh kh hp thu -ngay c cc nn kinh t quen vi thtrng lu). Thc vy dng nh c sli cun tc th gia cc nh l lun c cacnh t v ca cnh hu. C hai u b licun bi s hng say sng o, ch khngphi bi phn tch duy l. Do nhiu nh llun t chi h t tng ca Marx, hchp nhn h t tng th trng t do. Cmt chuyn a rng Milton Friedman lnh kinh t hc c knh trng rng ri

nht Lin X - mc d sch v cc bivit ca ng th cn phi c. ng l mtbiu tng ca mt h t tng, v lmt h thng nim tin kh d khc m htm kim.

Tt nhin c nhiu loi thuc v bngchng giai thoi - s thc l cc nn kinht th trng hot ng tt lin tc cthut li. Chng c giai thoi cho dchc chn tt hn khng c chng c g-ch l cng rm yu t t c s cho sla chn mt h thng kinh t. Chng cgiai thoi ca mi lm nm trc anhiu ngi vit sch gio khoa (k cPaul Samuelson) gi rng c th c snh i no gia quyn t do v tngtrng - rng cc nn kinh t x hi chngha thc ra tng trng nhanh hn ccnn kinh t th trng. Nhng tho lun

c a chung ca thi i gi rngdn ch v quyn t do c th l nhng thxa x m ch nc giu mi c th sc:Nhng nc cam kt cho tng trngnhanh c l phi chn con ng x hich ngha, ngay c nu dng nh c mitng quan (tt yu hoc khng) gia conng v s mt quyn t do. Ngay ccc nc khng chp nhn hon ton mhnh X-vit h khc c thuyt phcrng mt s c tnh ca n - k hoch hotp trung, cng nghip ho mnh m, shu cng cng i vi cc t liu sn xutc bn, t l tit kim bt buc cao lnhng thnh t quan trng ca bt kchng trnh pht trin thnh cng no.Ngy nay nhn t phi cnh lch s himc ca vi nm mun hn - tt c nhngxt on kinh nghim u b nghi ng.

(Tt nhin c nhiu nh kinh t hc chngbao gi nao nng trong nim tin ca h vith trng, by gi nhng ngi y niti bo m. Nhng mt s trong s hcng ging nh cc nh phn tch chngkhon lun tin on cc th trng gixung hoc th trng gi ln. Ngy vngson ca h cui cng n, nhng iuny khng th c cho l hoc do snhy bn ca h hoc do tnh nghim tcca phn tch ca h). Hn na, chng cgiai thoi cn xa mi r rng lin quann tin trnh hnh ng no cc nc nyphi tin hnh: Mt l gii thng dngcho s thn k Chu - s tng trngnhanh ca Nht bn, Hn Quc, Singapore,v i Loan- l chnh ph ng mt vaitr thit yu trong chi phi th trng.[4]

Khi ti hi, Liu khoa hc kinh t cng gp nhiu cho nhng tho lun ny?ti mun nhiu hn vic thut li chng cgiai thoi v s lp i lp li nim tin cacc nh kinh t hc vo th trng: Liu ccc nh l no ch cho chng ta rngcc nn kinh t th trng s nht thit lmtt hn cc nn kinh t x hi ch ngha,hoc liu t nhn ho s ci thin tnh hiuqu ca cc doanh nghip quc doanh?Liu c cc kt qu gii tch no chochng ta bit cht g v s cn i vvai tr ca chnh ph v khu vc t nhn v hu ht cc trng hp thnh cng linquan n cc nn kinh t hn hp vi ccchnh ph ln. Chuyn i sang mt nnkinh t th trng khng i hi lm hotn nh nc m l s ti xc nh vai trca n. Khoa hc kinh t phi cung cp s

ch dn no cho cc ch ny?Trong sut na th k qua mt h

thuyt n gin chi phi nghnh kinh thc - c nhc n mt cch khc nhaunh h thuyt cnh tranh (competitiveparadigm), hoc tn c in, hoc m hnhWalras. Pht biu chnh xc nht ca hthuyt y c cung cp bi m hnh caArrow v Debreu (1954; xem c Arrow1951b; Debreu 1959). N a ra nh v s ng cc x nghip ti a ho linhun vi cc khch hng duy l, ti aho tho dng trong mt nn kinh t trong c mt tp ca cc th trng cnhtranh hon ho cho mi hng ho, trongmi giai on, trong mi trng thi tnhin (cho mi ri ro), mi a im.Hu ht nhng ngi, cho rng m hnh cnhiu iu ni v th gii thc, u tin

rng nhng kt lun ca n l vng chii vi vic gim cc gi thit chnh xcc Arrow v Debreu s dng (th d,lin quan n tnh y ca cc thtrng).

Ti mun lp lun trong cc bi gingny rng h thuyt cnh tranh khng nhngkhng cung cp my ch dn cho vn ct t v la chn cc h thng kinh t, mli khuyn n cung cp thng l sailc. Cc quan nim v th trng to c scho phn tch m t sai c im can; nhng phn tch chun nh gi thpnhng im mnh v im yu - ca ccnn kinh t th trng, v nh th cung cpcc tn hiu sai cho s thnh cng timnng ca cc kh nng la chn khc vcho vic th trng c th c ci thin.Cng nh th, khng th da vo h thuyt

a ra nhng ch dn cho cc nnkinh t nguyn x hi ch ngha khi h tmcch xy dng cc h thng kinh t mi.

Vn c bn vi m hnh tn c inv m hnh tng ng to c s cho chngha x hi th trng [5] l chng khngtnh n mt lot vn ny sinh do sthiu vng thng tin hon ho v chi ph kim thng tin, cng nh s thiu vnghoc s bt hon ho trong nhng thtrng vn v th trng ri ro [bo him]ch yu. S thiu vng hoc bt hon hoca cc th trng ny, n lt chng, aphn li c th l gii bi cc vn thngtin. Trong mi lm nm qua, mt hthuyt mi, i khi c nhc ti nh cchtip cn l thuyt thng tin i vi kinh thc (hoc, ni gn, h thuyt thng tin),[6] c pht trin. H thuyt ny cng

khai quan tm n nhng vn ny. [7]H thuyt ny cho chng ta ci nhnthu hiu vo kinh t hc pht trin [8] vkinh t hc v m. [9] N cp cho chng tamt tn kinh t hc phc li mi, [10] mtl thuyt mi v doanh nghip, [11] v mts hiu bit mi v vai tr v s hotng ca cc th trng vn. N cho chngta s thu hiu mi lin quan n cc vn truyn thng, nh thit k cc c cukhuyn khch.

Nhng mi quan tm l thuyt thng tinny khng ch lm giu v thay i cccu tr li cho cc vn kinh t truynthng; chng cng dn n cc vn miphi t ra. i vi ba vn c in cakinh t hc - phi sn xut ci g, phi snxut ra sao, v phi sn xut cho ai bygi chng ta a thm vn th t cc

quyt nh ny phi c tin hnh ra saov ai phi ra cc quyt nh . Trong nnkinh t ca Joan Robinson (hoc Arrow vDebreu), cc nh ra quyt nh, v c cuca vic ra quyt nh, khng ng vai trno. Joan Robinson m t cng vic canh qun l ca mt doanh nghip ch nthun l ng vo cun sch k hoch trang thch hp tng ng vi gi c ccyu t sn xut hin thi (v tng lai).Trang s cho bit cng ngh no tithiu ho chi ph vi cc gi c yu t y.Cuc sng tht n gin! Tt nhin, nugi nh cuc sng n gin th, lm mtnh qun l s thc s l mt vic nhmchn, ng nh hn lm Anh khinh, vvic thiu quan tm ca Lange, Lerner, vTaylor n nhng khuyn khch qun l schng my quan trng: v c bn h [nh

qun l] c th c thay bng cc automat[my t ng].

Tm li, trong cun sch ny ti munch ra nhng trin vng ca h thuyt thngtin mi ny c th cung cp t nht mt sthu hiu hn ch ra sao vo cc vn cn bn i mt cc nn kinh t nguyn xhi ch ngha. Ngoi ra ti mun cpmt s vn c bn, lu di trong lthuyt v t chc kinh t: ti mun chngt rng phn ln ca cuc tranh lun c qua v s ng kht khao ca ch ngha xhi th trng lm lc; n da trns hiu bit sai lm v cc th trng cnhtranh hot ng ra sao, mt s hiu lm mm hnh Walras c th gp phn khngnh. (Nhng ngi o, ti tin, cmnhn iu ny, v h c gng to ra mtvin cnh kh d khc v nn kinh t th

trng. Nhng h chng thnh cngtrong din t v hnh thc ho cc quanim ca h dng hon ton tho mnvi t cch l mt h thuyt nht qun thaycho h thuyt Walras, v nh th, ngoimt s dn chiu ch thch i khi, h vn ngoi tro lu chnh, t nht ngoi trolu M/Ty u. Ti s c nhiu iu ni v quan h gia cc tng trnh by y v truyn thng o mun hn trongcun sch ny. [12] )

Sau khi gii thch nhng hn ch cacc l thuyt v tranh lun ban u, ti sc gng din t ci ti xem l cc vn c bn, nhng s thu hiu c th lm ltc t ci m chng ta hc trongmi lm nm qua, v cc vn vn cnphi gii quyt. Ti s kt thc cun schvi mt s nhn xt gng th p dng cc

bi hc hc c vo cc vn chuyn i ang i mt cc nc ngu. [13]

Nhng kt qu truyn thng v cch thng kinh t so snh

Khong chng mi hoc mi lmnm trc khoa kc kinh t c ba nhmkt qu hng dn nhng ai mun lachn cc h thng kinh t kh d.

Cc nh l c bn ca kinh t hcphc li v bn tay v hnh ca AdamSmith

u tin, c cc nh l c bn cakinh t hc phc li (Arrow 1951b;Debreu 1959), pht biu l l ni ting caAdam Smith v bn tay v hnh. Smith lplun rng khng ch cc c nhn c dndt bi bn tay v hnh thng qua chytheo t li theo ui li ch quc gia,

m chnh s chy theo t li ny l cchcch tin cy hn nhiu m bo rngli ch cng cng c phc v so vi btk la chn kh d no khc - chc chntt hn vic da vo nh lnh o chnhph no y, du cho nh lnh o y c nh tt n u. L l ca Smith to ra nntng da vo cc nn kinh t th trng.

Cc nh l c bn ca kinh t hcphc li chnh xc ho ngha v cc iukin theo cc th trng c hiu qu.nh l thng c nhc ti nh nh lc bn th nht ca kinh t hc phc lich ra rng di nhng iu kin nht nhmi cn bng cnh tranh l c hiu quPareto - tc l, mt trng thi ti hn trong khng ai c th kh gi hn m khnglm cho ai b t hn. Ci thng cnhc ti nh nh l th hai ca kinh t hc

phc li a ra cc iu kin theo btk phn b ngun lc c hiu qu Paretono u c th c thc hin thng quacc c ch th trng. Cc nh l c bnca kinh t hc phc li to nn tng cacch tip cn khuyt tt th trng chocan thip ca chnh ph. [14] Cc thtrng khng hot ng hon ho khi cnhng nh hng ngoi lai quan trng, vv th c l do cn bn cho cc loi thu nhim. Cc th trng khng cung cp cchng ho cng cng, v v th c l do cnbn cho chi tiu cng cng v ng s,quc phng, v cc cng vic cng cngkhc. Phn b th trng ca thu nhp cth l khng c nh mong mun v mtx hi, v v th c l do cn bn cho ccchng trnh ti phn phi ca chnh ph.

Cch tip cn khuyt tt th trng lp

lun rng thc s c mt vai tr cho chnhph, nhng ch l vai tr hn ch: Chnhph n gin ch cn sa cc khuyt tt thtrng c xc nh r, vic n c thlm vi cc cng c n gin c nhhng ti thiu n phng thc hot ngca nn kinh t th trng. Th d, cc vn v nh hng ngoi lai c th c cp thng qua cc khon thu hiu chnh(thu Pigouvian). Ngay c khi chnh phkhng chc chn v thu sut no s tcc mc tiu kim sot nhim ring bit,c ch th trng c th c s dng:Chnh ph c th cp cc giy php nhim c th mua bn c. [15] Chcchn l, chnh ph c nhng trch nhimhn ch khc na: n phi cung cp cchng ho cng cng v phi thu thu titr chng. N cng c th phi c nhng

hnh ng m bo rng cc th trngl thc s cnh tranh. nh l c bn thhai ca kinh t hc phc li phc ho tipvai tr hn ch ca chnh ph: Ngay c nuti phn phi thu nhp l khng tho mn,ch cn n can thip hn ch ca chnhph. Tt c ci m chnh ph phi lmch l ti phn phi cc khon tr cp theophng thc trn gi (khng mo m).

ng sau c hai nh l l quan nimrng h thng gi c cung cp mt cng chng hu cho phn b ngun lc. Nhngtrnh by gio khoa v nng lc ca hthng gi thng i qu cc tng cphn nh trong cc nh l c bn ca kinht hc phc li, ni v tnh hiu quthng tin ca nn kinh t th trng v hthng gi. Chng ai cn bit y v sthch ca cc c nhn, cc cng ngh sn

xut, v s sn c ca cc ngun lc.Chng ai thm ch cn bit n vic lm ramt mt hng n gin nh chic bt chth no. Gi c truyn t thng tin v skhan him ca cc ngun lc. Chngtruyn t thng tin t cc h gia nh ncc x nghip lin quan n ngi tiudng mun g, v t cc x nghip n ccgia nh v cc chi ph ngun lc linquan n tiu th mi mt hng. H thnggi m bo rng nn kinh t sn xut ccmt hng m cc c nhn mong mun.

Trong khi nhng ngi ng h kinh tth trng thng thi v ho v p vquyn nng ca n, cc nh l lm nn chos khoa trng thc ra chng ni my vthng tin. Cc nh l, th d, khng tholun nn kinh t x l thng tin mi tt rasao - thc ra trong cc m hnh ca chng,

khng c dng thng tin mi cng chngni liu n c hiu qu trong phn bngun lc thu lm thng tin tho ngcho vic phn b ngun lc. N thm chkhng tha nhn s xung t gia tnh hiuqu, theo nn kinh t truyn t thngtin v tri thc, v nhng khuyn khch hinc cho thu thp thng tin v tri thc: Nu,th d, cc gi th trng c phiu chuynti thng tin mt cch hon ho v tcthi, th chng nh u t no cn bt kkhuyn khch no kim thng tin. Ccth trng c phiu phi c c trngbi thng tin khng hon ho, chng nothng tin l t . C, nh Grossman vStiglitz (1976, 1980a) din t, mtlng cn bng ca bt cn bng. Nhngcc nh l cn bn ca kinh t hc phcli tuyt i chng c g ni v lng

cn bng ca bt cn bng l hiu qu theobt k ngha no. Th d, liu cc chi phcho thu thp v phn pht thng tin l qut, qu nhiu hay va ?

Theo cch tng t, i vi cc nhsng ch hay i mi nhn c khonli trn cc hot ng sng ch ca h,khng th c s truyn b t do tri thccng ngh. Nh tho lun di y ca tis nhn mnh, cc vn thng tin m nnkinh t th trng cnh tranh gii quyt chiu qu l cc k hn ch.

nh l Lange-Lerner-TaylorNhm kt qu th hai i khi c

nhc ti nh nh l Lange-Lerner-Taylor.N lin quan n vic thit lp s tngng gia hai la chn kh d v sp xpnh ch cho nn kinh t; n khng nh stng ng gia cc nn kinh t th

trng v ch ngha x hi th trng.Ch ngha x hi th trng l mt

dng t chc kinh t trong chnh ph shu cc t liu sn xut (nh di bt kh thng x hi ch ngha no) nhng dnggi c theo cch nh cc nn kinh t thtrng dng phn b ngun lc. Dich ngha x hi th trng cc nh qun lc ch th ti a ho li nhun, nhcc nh qun l ti a ho li nhun chngha t bn. Gi c c nh sao chocu bng vi cung.

Nhng khc bit ch yu gia cc nnkinh t th trng v ch ngha x hi thtrng l cc c ch theo gi c cnh ra v ch s hu vn. nh gidi ch ngha x hi th trng, mt cquan chnh ph lp k hoch thay th vici i li li ra thng trng hoc thay

nh u gi kiu Walras huyn thoi. [16]S thc l vn c chnh ph s hu cngha rng thay v cc c ng nhn c tc(biu hin li nhun ca x nghip), th ctc c chuyn cho chnh ph.

Mt h qu ca vic chnh ph s huvn l chnh ph phi gnh vc trchnhim phn b vn. Trong hu ht nhngth hin ca ch ngha x hi th trngchnh ph khng lm iu ny bng mtcn bng cung v cu (theo cch cc mthng khc c phn b) m thay vo bng mt c ch phn b trc tip hn.[17] Nhng nu chnh ph phn b vntheo cch chnh xc nh cc x nghip tnhn phn b, th nhng phn b ngun lchin ra t hai h thng s ging ht nhau.

tng v ch ngha x hi th trng l mt tng mnh m. N gi rng

c th c tt c nhng u im ca cc nnkinh t th trng m khng c nhngnhc im km theo ca s hu t nhnv nhng s tp trung ln ca ci thngi km. Ch ngha x hi th trng, ngita ngh, c th ng thi loi tr nhngcm by m ch ngha x hi kiu X-viti mt. iu ny i hi rng v c bntt c mi thng tin v cng ngh [18] phic truyn ti nh lp k hoch trungng, ngi tin hnh hng triu quytnh lin quan n mt hng no phi csn xut v sn xut ra sao. Nh lp khoch trung ng s phi quyt nh minh my phi sn xut nhng mt hng no,v phi chuyn ch u ra ca n i u.Hayek ph phn quan im ny mtcch ng n, lp lun rng nh lp khoch trung ng chng bao gi c thng

tin cn thit. Ch ngha x hi th trngdng nh gi rng nh lp k hochtrung ng chng cn c tt c thng tinchi tit ngoi vai tr ca mnh trong phnb u t, nh lp k hoch trung ngchng lm g hn nh u gi kiu Walras,mt tc nhn quan trng trong din gii ccnn kinh t cnh tranh. Cc nh l ca kinht hc phc li nng cao nng lc ca chngha x hi th trng: nh l cn bn thhai m bo rng chnh ph c th, thngqua ch ngha x hi th trng, t bt kkt qu c hiu qu Pareto no.

Trong thp k qua Hungary v mt snc khc c gng theo con ng chngha x hi th trng (hoc t nht theoci m h coi l mt s thch nghi ca mhnh y) vi thnh cng kh hn ch. [19]Nhng tht bi c v ny ca cch tip cn

dn ti hai phn ng. Mt s ngi, tnht trong chc lt, c mong mun quayli vi cc h thng phi th trng; trongkhi a s mong mun tin nhanh theo conng dn ti th trng. Hu ht mingi cng ngy cng nghi ng v khnng tn ti ca loi con ng th ba idin bi ch ngha x hi th trng.

Chng ta phi quy tht bi ca chngha x hi th trng cho ci g? nh lLange-Lerner-Taylor, khi kt hp vi ccnh l cn bn ca kinh t hc phc li,gi rng nn kinh t phi c kh nng tbt k kt qu c hiu qu Pareto no. Tacn ch mong g nhiu hn t cuc sng,hoc t nht t nn kinh t?

V cc nn kinh t k hoch ho tptrung v h thuyt tn c in

Sut cun sch ny ti s tp trung vo

so snh gia cc th trng v ch nghax hi th trng, ch khng phi, th d,vo so snh gia cc th trng v cc nnkinh t k hoch ho tp trung, chc phir l nhiu vn m ti nu ra ycng p dng cho so snh . Mt trongnhng lp lun ca ti l, gi nh m hnhtn c in ca nn kinh t l ng, th chngha x hi th trng hn s thnh cng;bng cch tng t, nu gi nh m hnhtn c in l ng n, th ch ngha xhi k hoch ho tp trung vp phi tvn hn n thc s vp phi.Samuelson m t nn kinh t nh ligii cho bi ton ti a ho; nh l cnbn ca kinh t hc phc li ch ra rngvi cc gi thit mnh th s thu hiu cang l ng. [20] Ngoi ra, cc k thutton hc, nh quy hoch tuyn tnh, kt

hp vi cc my tnh tc cao, gi rng c kh nng gii trc tip ra ccphn b ngun lc hiu qu. Nh ti nhc ti trn, m hnh Arrow-Debreugi rng cc th trng cnh tranh l giithut hiu qu gii bi ton phn bngun lc ca nn kinh t, nhng cc kthut v cng ngh mi ny gi rngchng ta c th khng cn n gii thut do b qua mi vn gn vi c chth trng m vn nhn c li gii chovn cc ngun lc ca x hi phi cphn b mt cch c hiu qu ra sao. [21]

(C l ng nhc ti l trong khi nhngcng trnh ban u v cc gii thut giicc bi ton ti a ho phc tp gi rngnhng gii thut dng gi c [s dngtnh i ngu] v phn quyn c vtng t nh cch cc th trng gii bi

ton phn b ngun lc l nhng giithut hiu qu, cc cng trnh mi y hn to ra cc gii thut hiu qu hn nhngci dng nh khng c bt k ci tngt th trng no. iu ny h tr choquan im ca ti rng, ci l vn trongphn tch v nn kinh t phn b ngun lcca mnh ra sao nhiu hn l li gii nthun cho mt bi ton ti a ho phctp: kinh t hc l phc tp hn nhiu, vl th hn, so vi cch tip cn k thutng dng thnh hnh trong cc thp nintheo sau C s ca Phn tch Kinh t[Foundations of Economic Analysis] caSamuelson). [22]

nh l (hoc phng on) ca CoaseNhm cui cng ca cc tng

thng c nhc ti nh nh l Coase(tuy chng bao gi c pht biu dng

chnh xc ng c tn gi ).Coase nhn mnh tm quan trng ca ccquyn ti sn. Theo Coase, nu cc quynti sn c phn r rng, th cc c nhnc khuyn khch thc hin nhng dnxp kinh t hiu qu. Khng quan trnglm l ai nhn c cc quyn ti sn (ttnhin, iu ny nh hng n phn phica ci) ging nh ngi no c.Nhng s phi hiu qu nh "Thm hong c" - chn th gia sc n c mtcch qu ng trn ng c chung, khoannhanh qu th cc ti du chung, nh btc qu ng vng bin quc t - l ktqu ca s tht bi trong phn cc quynti sn. Nhng s phi hiu qu khc nysinh t hn ch cc quyn ti sn: Tht bitrong vic cho php cc quyn v ncc mang bn dn n phn b sai v

nc min ty ca Hoa K.Cc nn kinh t x hi ch ngha ngh

mnh ph hu nhiu quyn s hu tnhn, v nhiu tht bi ca ch ngha xhi c cho l v iu : Nhng ngi trong cc cn h khng c nhngkhuyn khch bo tr cn h ca h, biv h khng th chim c bt k khonli no t cc hot ng y khi bn cn h(ht nh cc th, vi kim sot tinthu, i mt vi cc vn tng t).[23] Cc nh qun l ca cc x nghipquc doanh c nhng khuyn khch khngtho ng, h khng th gt hi c y li ch ca cc n lc ca mnh.

Nhn t vin cnh hin thi, cc nnkinh t x hi ch ngha t thnh cnghn trong vic hu b cc quyn s hu tnhn nh h c th ngh; bi v cc nh

qun l c quyn t ng k trongphn b (thng vi gi qu thp) snphm u ra (thng p li nhng ui tng t t cc nh qun l khc). Viclm m mt c nhn khng th b sa thi cth xem tng t nh "quyn s hu". Ttnhin chng l nhng quyn s hu hnch: Ngi cng nhn, th d, khng thbn vic lm ca mnh cho mt ngikhc. V bi v cc quyn s hu l hnch, nn ny sinh loi mo m. Vincnh Coase c mt n thuc r rng: Chngha x hi th trng, ging nh bt khnh thc no khc ca ch ngha x hi,c s phn bi t, n gin bi v ccquyn s hu trong ti sn khng c xcnh r rng. Khi ti sn c s hu bitt c mi ngi, th thc ra chng ai shu c, khng ai c khuyn khch thch

ng. Theo vin cnh ny, th, nhim vu tin trong nn kinh t chuyn i l tnhn ho ti sn nh nc.

Trong khi lp lun rng s thiu vngcc quyn s hu t nhn c xc nhr rng, hoc b hn ch, thng gy ranhng mo m l l l ng, cn nhng ktlun c bn khc th khng. Th nht, sphn r cc quyn s hu khng nht thitdn n hiu qu. Cc vn hng hocng cng, th d, [24] khng c giiquyt bng nh l Coase. Trong khi Coasev nhng ngi theo ng ch ltqua n kh nng l cc chi ph giao dchc th cn tr cc bn "mc c" ra mt ktqu hu hiu, vi s hin din ca thngtin khng hon ho (gy ra ci c th ccoi nh cc chi ph giao dch), kt qukhng hiu qu thng ny sinh; tht vy

cc thng v cng c li c th n ginkhng xy ra, khi mt bn c thuyt phcbn kia rng gi tr ca mi quan h ivi anh ta l nh, trong n lc nhm chimphn ln hn ca gi tr thng d sinh rat mi quan h (xem, th d, Farrell 1987).[25]

Th hai, s thiu vng cc quyn shu t nhn c xc nh r rng khngnht thit gy ra cc vn . C nhiu tiliu ngy cng tng chng t rng, trongcc bi cnh khc nhau, cc cng ng aphng trnh "Thm ho ng c" rasao bng cc cng c iu tit a dng.

i th hn, c mt s nghi ng lius thiu vng cc quyn s hu c xcnh r rng c phi l vn trng tmkhng. C hai chng c ng h iu ny.Th nht l hu ht cc cng ti ln u

khng c cc ng ch iu hnh m docc nh qun l c thu iu hnh. Cuhi liu c s khc bit chng khi nhqun l lm vic cho mt nhm tp nhamcc c ng, hoc lm cho nh nc, lvn m ti s quay li sau. [26] Thhai l s tng trng nhanh Nam TrungQuc: s thiu vng cc quyn s huc xc nh r rng khng cn trtc tng trng hai con s.

Khng ch l trng hp rng s thiuvng cc quyn s hu t nhn c thkhng l vn trng tm; thm ch cnkhng r l vi t nhn ho chnh ph cth t cc mc tiu ca mnh cng hiuqu nh n c th nu n kim sot trctip doanh nghip. Cu hi liu t nhnho p o kim sot cng cng l mtvn trung tm m ti s quay li

Chng 9. nh l c bn v t nhn hoc tho lun gi rng khng phith.

Cc ch trung tm ca cc biging ny

n y ti chun b xong c thpht biu y su ch ch yu cacun sch ny:

1. M hnh tn c in chun -din t hnh thc ho bn tay v hnh caAdam Smith, lun im cho rng cc nnkinh t th trng s m bo hiu qukinh t - cung cp t ch dn cho chn lacc h thng kinh t, v mt khi s bthon ho thng tin (v s thc l cc thtrng l khng y ) c a vophn tch, m chc chn phi vy, thkhng c c s cho gi nh rng cc thtrng l hiu qu.

2. nh l Lange-Lerner-Taylor,khng nh s tng ng ca th trngv nn kinh t x hi ch ngha th trng,da trn mt quan im sai lm v thtrng, v cc vn ct li ca phn bngun lc, v (khng ngc nhin khi chotrc hai khim khuyt u) v cch thtrng cp cc vn y ra sao.

3. H thuyt tn c in, thngqua s c trng sai lm ca n v ccnn kinh t th trng v cc vn chyu ca phn b ngun lc, to mt cmgic sai v nim tin trong kh nng ca chngha x hi th trng nhm gii quytcc vn phn b ngun lc . Phtbiu theo cch khc, gi nh h thuyt tnc in cung cp mt m t tt cho vn phn b ngun lc v c ch th trng,th ch ngha x hi th trng chc c

th thnh cng. Bn thn nhng ph phnch ngha x hi th trng, nh th v ith, l nhng ph phn h thuyt tn cin.

4. Cc vn kinh t ch yuvt qu ba vn truyn thng c tra u ca mi vn bn dn nhp: Snxut ci g? Sn xut th no? V sn xutcho ai? Trong s cc vn rng hngm: Cc quyt nh phn b ngun lcny phi c tin hnh ra sao? Nhng aiphi ra cc quyt nh ny? Lm sao cth khin nhng ngi c trch nhim racc quyt nh ny a ra cc quyt nhng n? Cc quyt nh tch ri nhauca hng triu con ngi -nhng ngi raquyt nh- trong nn kinh t c iuphi ra sao?

5. Ct li ca cc nn kinh t th

trng thnh cng l cnh tranh, cc thtrng, v phn quyn (phi tp trung). Cth c nhng iu ny, v chnh ph vnng mt vai tr ln trong nn kinh t;thc vy c th cn thit l chnh ph phing mt vai tr ln hn nu cnh tranhcn phi c duy tr.

Mi y c nhiu ln ln v s thnk ng , s tng trng nhanh ng kinhngc ca cc nc trong vng ny trongsut mt hai thp k qua, phi c quycho ci g. Cc nc nh Hn Quc sdng th trng; h rt hng v xut khu.V bi v cc th trng ng mt vaitr quan trng nh vy, nn mt s nhquan st kt lun rng thnh cng cah l chng c thuyt phc v nng lcca ring th trng. Th m trong hu htcc trng hp, chnh ph ng mt vai

tr to ln trong cc nn kinh t ny. Trongkhi Wade c th din t hi qu khi ngt tn cho cun sch ca mnh v thnhcng ca i Loan l Cai tr Th trng[Governing the Market], khng c mynghi ng rng chnh ph can thip vonn kinh t thng qua th trng.

6. Ct li ca s tht bi ca thnghim x hi ch ngha khng ch nthun l thiu cc quyn s hu. Cngquan trng nh th l cc vn ny sinhdo thiu khuyn khch v cnh tranh, khngch trong lnh vc kinh t m c trongchnh tr. Thm ch cn quan trng hn cl l cc vn v thng tin. Hayek ng, tt nhin, trong nhn mnh rng ccvn thng tin i mt vi nh lp khoch trung ng l qu ln. Ti khngchc rng Hayek nh gi tm ca

cc vn thng tin. Nu gi nh chngch hn ch loi vn thng tin nm trung tm ca m hnh Arrow-Debreu -nhng ngi tiu dng truyn t s thchca h cho cc doanh nghip, v cc gitr khan him c truyn t cho c ccdoanh nghip v nhng ngi tiu dng -th ch ngha x hi th trng c thhot ng. Th Lange l ng v bngcch dng gi c, nn kinh t x hi chngha c th "gii" bi ton thng tinnh th trng c th. Nhng cc vn thng tin l rng hn.

________________________________________[1]hm kh vi l hm s c th ly vi

phn, tc l c o hm.[2]Thm ch c mt s tranh ci v

mc m ch ngha x hi th trng thtbi, th d nh Hungary, ni n c th

lm cn mn nht. Hungary t l tngtrng ngay sau nhng ci cch ban u1968 l kh cao. S gim st t l tngtrng trong cc nm mun hn c th mtphn c cho l do suy gim cam kt cicch, v mt phn do nhng iu kin kinht ton cu gy ra s st gim tng trngtrong hu ht cc nc. Thc vy s gimst Hungary l t hn so vi nhiunc khc, d cho c ph phn rng iuny xy ra bi v Hungary khng thchng vi gi du thay i, v vay mn qunhiu t nc ngoi. S mc n quc tny l mt trong nhng vn chnh mHungary phi i mt ngy nay.

[3]Hoc, lin quan n ch , lloi ngho i c trng cho cc khungi da en Hoa K. C l ng nhcn rng, t nht theo cc thc o bt

bnh ng truyn thng, mt s nc angpht trin thnh cng nht, nh Hn Qucv i Loan, th hin mt mc bt bnhng cao.

[4]Xem, th d, Wade (1990) vAmsden (1989).

[5]Ti s tho lun mun hn v chngha x hi th trng ngha l g.

[6]Trong nhn mnh h thuyt thngtin, ti khng c b qua hay lm nhnhng ph phn khc i vi h thuyt tnc in c pht trin trong mt phnt th k qua. Mt s trong s , nhnhng ph phn nhn mnh tm quan trngca nhng bt hon ho trong cnh tranh,khng nhng ch nht qun vi h thuytthng tin; m trong nhiu kha cnh, cnhc ti sau, chng l b sung.

[7]V tng quan, xem Stiglitz (1975a,

1985c, 1990a), hoc Hirshleifer and Riley(1979). Bo co bao qut hn v nhiu mhnh c th thy trong Laffont (1989) vMilgrom and Robert (1992).

[8]Xem, th d, Stiglitz (1985a,1988a) v tuyn tp cc bi bo trnh byl thuyt mi ni ln v cc t chc nngthn do Bardhan (1989) ch bin v Hoff,Braverman, and Stiglitz (1993).

[9]Xem, th d, Greenwald andStiglitz (1987).

[10]Cho mt tng quan, xem Stiglitz(1987a).

[11]Trong l thuyt mi ny, s phnk (khc nhau) gia cc li ch ca cc cng v cc nh qun l, v gia cc nhqun l v ngi lao ng, c tha nhnmt cch tng minh. Nhng hn ch vnng lc ca cc th trng to k lut

cho cc nh qun l c gii thch, v ccvn mi c cp lin quan n ccdoanh nghip phi c t chc ra sao, tnh n c cc vn khuyn khch lncc vn ny sinh t s thc l thng tinth hn ch v t trong thu nhn vchuyn ti.

[12]Ph phn ca ti i vi cc cngtrnh o ban u vt qu tranh lun rngh to ra mt l thuyt cha y ; nhti s ch ra, mt s tng c bn, nhnhng tng lin quan n cc qu trnhtin ho v tnh hiu qu thng tin ca nnkinh t, c quan nim sai.

[13]Khi ti vit nhng bi ging ny,qu trnh chuyn i mi va bt u. Khicc bi ging ny n nh in, hn hai nmsau, phn ln nhng iu ti trnh by cv nh vn thch ng. Tranh lun v qu

trnh chuyn i cn l mt cuc tranhlun sng ng.

[14]Ti liu tham kho chun cho iuny l bi bo ca Francis Bator (1958).Cch tip cn ny hin nay to nn tngcho vic trnh by ca sch gio khoachun v kinh t hc ca khu vc cngcng. Xem, th d, Stiglitz (1988b).

[15]Chnh ph Hoa K mi y lmiu ny, v S Thng mi Chicago thct to cc th trng cho cc giy phpny, to thun li khng ch cho vic traoi m c vic u c v gi tr tng laica cc quyn ny.

[16]Vn khoa ban u v ch ngha xhi th trng pht trin trc nhngtin b trong ti chnh cng, trong nhthu ti u c th dn n nhng khc bitgia gi sn xut v gi tiu dng. Nhng

nh l Lange-Lerner-Taylor c th cm rng d dng bao hm nhng khcbit ny. Xem, c bit, Dasgupta andStiglitz (1972).

[17]Nh chng ta s thy mun hn,c l do chnh ng cho s khc bit trongx l: cc th trng futures (k hn) v riro cn thit cho phn b vn hiu qukhng tn ti trong cc nn kinh t t bnch ngha, v c th gi thit rng s khto nhng ci tng t hot ng trong chngha x hi th trng. Thc vy, cc nnkinh t t bn ch ngha da nhiu vo ccc ch phn b trc tip, tuy l cc c chphn tn.

[18]Trong m hnh X-vit, khngnhn mnh lm n s thch ca ngi tiudng, nhng c th gi thit rng, trongmt nn kinh t nh hng tiu dng hn,

th thng tin v s thch tiu dng cng sphi truyn t n cho nh lp k hochtrung ng.

[19]Cn mt li thn trng: Nhng cnnhc chnh tr, nht l gia v cui ccnm 1970, t ra cc rng buc cho mc m m hnh ch ngha x hi th trngc th c thc hin, ngay c Hungary.

[20]Tc l, c mt bi ton ti u hochnh xc theo mi phn b th trngcnh tranh thc t l li gii.

[21]Lange, mt nh tin phong ca chngha x hi th trng, c hi vng lncho nhng cng ngh mi ny, nh cchng t trong cun sch ca ng (Lange1967). (Phi nh rng, Lange trong mtthi gian di l mt quan chc cao cptrong chnh ph Cng sn Ba Lan, v theomi nh gi ng c nh hng ln ti

s tin trin ca cc chnh sch kinh t ).

[22]C l cng ng nhc n rngngay c nhng ph phn mnh m ca kinht hc tn c in, nh Joan Robinson,cng sa vo tm tnh ng nh vy, khi bm t vn ca nh qun l x nghip ltng trang ca cun sch k hoch phhp vi gi ca yu t hin thi (v tnglai).

[23]Nu khng c kim sot tin thu,th ngi ch c khuyn khch duy tunh ca bi v n nh hng n tin thuci c th c trch ra.

[24]V, nh ti lp lun sau, cc vn hng ho cng cng l tng qut hn sovi nhng tho lun truyn thng thnggi : Th d, chng ny sinh trong thuthp tri thc v trong gim st cc doanh

nghip.[25]ng ch l cc th d v cc

thng v cng c li khng c hontt, do mt bn c kim phn ln hn cagi tr thng d pht sinh t bn thn miquan h. Kt qu ca mc c ph thucmt phn vo cm nhn ca mi bn vpha bn kia s b nh hng ra sao nukhng hon tt thng v (im e do).Nu mt bn c th thuyt phc bn kiarng n c cc c hi bn ngoi tt hn,th n c th kim c thng v c lihn cho mnh. Mi bn khi mc c cchuyn thng tin nh vy, nhng c hiuqu, cc tn hiu nh th phi l t (nisung th r, v nh th cc tuyn bthng khng c chp nhn mnhgi). Mt cch chuyn t thng tin nhvy l chng t rng mnh sn sng ko di

thi gian t tho thun, thm ch (hocc bit) khi vic lm chm tr nh vy ltn km.

[26]Mun hn ti s tho lun mtnh l chng t rng cc c ng trongcc hng nhn chung khng thng nht vcc hnh ng m hng nn lm.

2. Tranh lun vch ngha x hi thtrng: Cch tipcn c bn

Tranh lun v ch ngha x hi nichung, v v ch ngha x hi th trngni ring, c mt lch s di, vi nhng

ng gp ng k vo cc nm 1930 caLange, Lerner, v Taylor, mt bn, vHayek, bn kia. c nhiu ch chocuc tranh lun ny. Mt s mt itrong nhng tho lun gn y, cn cc ch khc li c nhn mnh hn.

Th d, nhng tho lun hin i nhnmnh tnh ho huyn ca ch ngha x hith trng ny sinh t tht bi ca n tnh n cc vn kinh t chnh tr hc:Liu cc nh quan liu c nhng khuynkhch thc hin cc ch dn ca nhngngi ch trng ch ngha x hi thtrng? Nh vy nhng ph phn chngha x hi th trng lp lun rng s sosnh thch ng khng phi l gia chnhph l tng ho c cc nh x hi chngha mc nhin tha nhn v nn kinh tth trng, m l gia nn kinh t vn hnh

ra sao di s kim sot thc t ca chnhph v nn kinh t th trng. Nhngnhng tho lun c hn nhn mnh tnh hohuyn ca m hnh cnh tranh ca nn kinht: Cn c vo s ph bin trn lan ca litc tng dn, so snh thch ng khngphi l gia ch ngha x hi th trng vcc th trng cnh tranh, m l gia chngha x hi th trng v ch ngha t bnc quyn.

Nhiu iu xy ra trn th gii - vtrong l thuyt kinh t - trong hn nmmi nm k t khi cc cuc tranh lunln xy ra. Khng ch c vn t vthut ng c cc nh kinh t hc dng thay i, m c, ti tin, nhng tinb ng k trong khoa hc kinh t chophp chng ta xem xt li nhng vn cny nhn t cc vin cnh mi. Nhn li

cc vn ny t vin cnh ca h thuytthng tin mi, nh ti ni, l mc tiutrng yu ca cun sch ny. Nhng trckhi trnh by chi tit cc lp lun camnh, ti mun cung cp mt phc horng ln hn v nhng tin b mi ytrong kinh t hc tham gia vo cc cuctranh lun c xa ra sao. Ma mai thay mts trong nhng tin b ny to sinh khmi cho l l ng h ch ngha x hi thtrng - ht nh cc nn kinh t th chngha x hi th trng li ang trong qutrnh ri b n. ng thi mt s tin bny nu ra nhng vn mi lin quann c tnh cn thit v kh nng tn tica x hi ch ngha th trng.

V sao l thuyt hin i li c thgi mt v hp l ln hn cho chngha x hi th trng [1]

t nht hai trong nhng kt qu chnhca l thuyt kinh t hc hin i, c l, cng c nim tin vo ch ngha x hi thtrng.

Thiu cc th trng k hn (Futures)v vai tr ca chnh ph trong phn bu t

Hin nhin l, nu cc nn kinh t thtrng hot ng theo cch m nhngngi ch trng cho l nh th, th ccth trng trong cc hng ho v dchv c th trao i phi tn ti. Mt trongnhng gi thit c s trong m hnh, hinnay c coi l m hnh chun ca cc nnkinh t (cnh tranh) - m hnh dng nhto ra nn tng tr tu ca mi th lng tinm ta c trong nn kinh t th trng - l,tn ti mt tp ca cc th trng. yl mt gi thit mnh hn l n c v khi

nhn thong qua. Chc chn l, c cc thtrng cho st thp, lao ng, t ai, cphiu, cho ng cc; trong khi cc thtrng ny c th khng "hon ho" - cth khng c nhiu ngi mua v ngibn trong mi th trng ny nh chnh dung bi m hnh cnh tranh - v huht cc th trng ny c th khng ct chc theo cch m l thuyt chun hnhdung - vi mt nh u gi pht ra cc gicho n khi t mc gi lm cn bng thtrng (market clearing)- nhng vn cmt s ng thun rng m hnh c bnca cc nh kinh t hc cung cp mt phpgn ng, mt xp x tt, t nht cho nhiuloi hng ho v dch v ny.

Nhng gi thit rng tn ti mt tpy ca cc th trng vt qu imny. Phi tn ti cc th trng trn

khng ch hng ho v dch v ca hmnay c trao i m trn cc hng hov dch v tng lai c trao i. [2] Ttnhin c mt s th trng k hn: Ta cth mua ng hay la m cho giao hng bahoc su thng sau. Nhng i vi hu htcc hng ho v dch v (ngoi mt s tmt hng nng sn, cho k hn vi thngtrong tng lai) khng tn ti cc thtrng ni ta c th trao i hm naycho giao hng trong tng lai.

Cc th trng k hn ny l thit yucho vic tin hnh cc phn b u tng. Lo ngi v kh nng ca nn kinh tth trng trong phn b v iu phi ut theo cch hu ch v mt x hi ttnhin to c s cho vic mi gi chngha x hi trong c th k ny v th ktrc. Khng c cc th trng cn

thit th khng c gi c thc hin ccvai tr iu phi/thng tin, nhng ci lthit yu nu mt nn kinh t mun c hiuqu. Mi x nghip phi hnh thnh nhngk vng lin quan n gi c trong tnglai s ra sao, v nhng k vng li, mtphn, da trn nim tin ca n v cc xnghip khc s lm g. Cc x nghip khcth c n lc ln gi thng tin y bmt. Nh vy, thay v tr thnh mt c chcho iu phi cc quyt nh u t, ccnn kinh t th trng dng nh tokhuyn khch cn tr iu phi. Cnhiu s th hin trong th gii thc cakhim khuyt ny: i khi c s tham giaqu ng vo mt ngnh cng nghip, khikhc li pht sinh thiu ht. Thc ra, ngayc cc n lc can thip hn ch ca chnhph nhm cung cp thng tin cn thit

thng qua k hoch hng dn [indicativeplanning] [3] (nh Php) xem ra thtbi, v cc x nghip dng nh thiukhuyn khch tit l trung thc k hochca h (v trong nhiu trng hp c thc nhng khuyn khch chin lc cungcp khc i ch khng phi thng tin trungthc).

Phi c cc th trng khng ch chocc thi k trong tng lai gn k m chomi thi k ko ra mt cch v tn votng lai xa. Khng c mt tp y cacc th trng k hn ko ra v tn ntng lai xa, th nn kinh t c th i theomt qu o hiu qu cc b v nht thi -ging ht nh mt qu o k vng duy lbnh thng, vi li tc thc t (li vncng t) trn mi ti sn l bng nhau - vch trong tng lai xa mi tr nn r rng

rng nn kinh t l phi hiu qu. Dngnh khng c nhng khuyn khch t nhnno hiu chnh kh nng ny i vitnh phi hiu qu c v tm di hn.Trc gic nm sau kt qu ny l n gin.Hy xt mt x nghip, trong nm 1990, dtnh xy mt nh my, d kin s dngtrong hai mi nm, v sau s bn chox nghip khc. ly quyt nh, n philp mt c tnh gi tr to nh cui thik hai mi nm, tc l, vo nm 2010.Nhng gi tr ca to nh y cui haimi nm s ph thuc, mt phn, vocung ca cc to nh khc c xy dngtrong khong t nay v hai mi nm na.Thm ch cc quyt nh s ph thucvo nhng k vng lin quan n ci g sxy ra cn xa hn na trong tng lai. Hyxt, th d, mt to nh c cn nhc xy

ct trong mi nm na, tc l vo nm2000. Cc ch ca n s mun bit liu hs c th bn to nh c bao nhiu, thd, hai mi nm sau khi xy dng, tc ltrong nm 2020. Gi tr ca mt to nhtrong nm 2020 s ph thuc vo cung cacc to nh ti thi im , ci n ltn li s ph thuc vo mc xy dng giahm nay v nm 2020. By gi hy xtmt to nh d kin xy vo nm 2010.Cc ch s hu ca n mun bit gi trca to nh vo nm 2030, v vn vn.Nh vy cc quyt nh hm nay c linkt mt cch khng th tch ra khi ci sxy ra trong mt mng li lin kt m rami mi. Trong thc tin, cc x nghipkhng theo qu trnh suy din phc tpny. Cc nh qun l kinh doanh t c scho cc quyt nh ca mnh trn linh cm

v c on. im ct yu ca lp lun lthuyt ch l: Ngay c di cc iu kintt nht, vi cc nh qun l tin hnh ccphn tch duy l nht, do s thiu vng cacc th trng m ra v tn vo tng lai,th chng c g m bo rng cc thtrng dn n cc kt qu hu hiu. Chcchn, nu cc nh qun l kinh doanh ctngn vic ny, bng cch tin hnh nhngtnh ton t tinh vi hn, th nim tin cachng ta vo tnh hiu qu ca cc kt quth trng s phi thm ch yu i na.

ng hc di hn: Mt on lc mang tnh k thut

c nhn ra t lu rng ng hcca cc m hnh ti u ho to ra cc quo im yn nga (th d, Samuelson andSolow 1953); tc l, vi cc vn "ngx-tt", c mt qu o duy nht, bt u

t bt k tp no ca cc iu kin banu, tho mn cc iu kin hiu qu giak (intertemporal) s hi t n trng thidng. Tt c cc qu o khc tho mncc iu kin hiu qu gia k u khnghi t (phn k). Mc d vy y khng lmt vn kinh t nghim trng; lun cmt iu kin na, iu kin v tnh ngang(transversality) phi c tho mn dctheo qu o ti u, v iu kin ngang nym bo s hi t n trng thi dng.Hahn (1966) ch ra rng cc vn tng t ny sinh nu c nhiu hn mt tliu sn xut trong m hnh m t ca nnkinh t. Nhng, ng lp lun, vi s thiuvng cc th trng k hn ko di v tnvo tng lai, th khng c m bo nocho s hi t ca nn kinh t n trng thidng. Cc cng trnh tip theo (Shell and

Stiglitz 1967) ch ra rng s bt nnh ca nn kinh t c th c loi trnu gi thit v kh nng thy trc honho (cc k vng duy l) c thay thbng cc gi thit khc lin quan n cck vng, nh cc k vng thch nghi, vitc thch nghi chm. Cng c chra rng nhng c im khc ca nn kinht c th to ra cn bng l mt nt nnh; th d, trong mt m hnh v tin tv tng trng, Shell et al.(1969) ch rarng t bt k gi tr ban u no cakhon vn v cung tin danh ngha, cnhiu qu o hi t cng n mt trngthi dng. Cc nghin cu khc (Stiglitz1973a) ch ra rng c nhng cn bngk vng duy l, tuy chng khng hi t nmt trng thi dng duy nht, chng cngkhng "n tung". Thc ra ng ch ra rng

c v s cc qu o khng hi t nhtqun vi cc k vng duy l.

Tht l k, cng cc kt qu gii tchli c th c l gii theo nhng cchkhc nhau. Cc cng trnh c hn tronglnh vc ny (Samuelson 1967; Hahn1966, Shell, Sidrauski, and Stiglitz 1969) ngh rng cc cn bng im yn ngal mt vn i vi nn kinh t t bnch ngha, v thiu cc th trng k hnko v tn vo tng lai, khng c cchno m bo rng nn kinh t s chn quo duy nht hi t n trng thi dng.Chc chn, s tn ti ca v s cn bng(i din bi trng hp nhiu qu o hit n trng thi dng) gy ra vn : Thnht, nn kinh t c th khng c kh nngtin on qu o no n s chn; v thhai, mt s trong s nhng qu o ny c

th "tt hn", theo mt ngha no , sovi cc qu o khc, v chng c mbo no rng nn kinh t s chn ra quo tt hn y. Nhng cc nh kinh t hcny quan tm nhiu hn n vn btn nh kinh t, v tnh phi hiu qu hinnhin c th xy ra (v c th l rt ln),so vi c l nhng khc bit nh trongphc li lin quan n s la chn mtqu o hi t ch khng phi qu okhc.

Ngc li, trong vn khoa v cc kvng duy l mi y, cc im yn ngac coi l tt, cn cc nt l xu. Nhngngi trong trng phi k vng duy l mun ch ra rng nn kinh t th trng lhiu qu. Bng cch chng t rng tn timt qu o duy nht tho mn cc iukin k vng duy l - nu h c th chng

minh rng (1) qu o duy nht l quo "ti u v mt x hi", v (2) nn kinht lun lun ng x nht qun vi cc kvng duy l - th h coi l h chngminh rng nn kinh t th trng c hiuqu. Ngc li, vi cc nt, c nhiu quo xut pht t bt k iu kin ban uno. Lm sao c th ni nn kinh t s theoqu o no? V do khng phi tt c ccqu o ny c hiu qu Pareto, cc ntgy ra kh nng l nn kinh t s khngtheo mt qu o hiu qu.

ng lu rng mi trong nhng githuyt to c s cho phn tch nhng kvng duy l u ng ng. Nh vy khngch c th l khng c mt cn bng kvng duy l, tr vi cc iu kin mnh,m cn bng cc k vng duy l c thkhng c hiu qu Pareto, nh ti s ch ra

chng tip theo. Nhng quan trng nhti vi mc ch hin thi ca chng ta, lkhng c l do tin rng - khng c ccth trng k hn ko di v tn vo tnglai, ngay c nu c mt qu o duy nhthi t n trng thi dng- nn kinh t thtrng s "chn" qu o . Lun iuca nhng ngi c cho rng nn kinh tth trng (vi nhng k vng duy l) l chiu qu, v s chuyn ng theo qu o(duy nht) hi t n trng thi dng,khng da trn li gii ca cc vn mHahn v nhng ngi khc nu ra. Cc vn ny n gin b b qua. Ngi ta githit rng nn kinh t hot ng gi nhnu c mt c nhn duy nht ti a ho stho dng ca mnh trong thi gian v tn.C nhn ny m bo rng iu kin ngangs c tho mn - v cng vy, ngi ta

qu quyt rng nn kinh t cng th. Sthc rng cc th trng k hn ko di vtn vo tng lai l cn thit n gin b b qua.

Tm li, d c l do hin nhin rngdo thiu cc th trng k hn th h thnggi khng thc hin vai tr iu phi thityu ca n lin quan n cc hot nghng ti tng lai, nh u t, hay ccc l do tinh t hn nh va c tholun, rng do thiu cc th trng k hnm ra v tn vao tng lai xa, nn kinh tth trng chc s c nhng bt n nhng hc - chng c l do g tin rngngay c vi cc k vng duy l n s hi tn trng thi dng; chng c c s no gi nh rng cc th trng, t chng,s l hiu qu. i vi nhng ngi chtrng ch ngha x hi th trng, h qu

ca phn tch ny dng nh r rng: Cnc mt loi kim sot ca chnh ph ivi phn b u t c hnh dung trongch ngha x hi th trng.

Vn ngi u thc-ngi i l vs tch bit ca ch s hu v kim sot

Nhng tho lun sm hn v ch nghax hi th trng t ch n vn cc khuyn khch. Cc nh qun l ti aho li nhun, vi gi do Ban nh gi acho h, bi v h c bo lm vy, v hlm ci h c bo phi lm. Thiu khnng xem xt cc khuyn khch i vi nhqun l l mt trong nhng ph phn mnhm nht i vi ch ngha x hi thtrng. Ngay c trc cuc tranh lun vch ngha x hi th trng ca cc nm1930, cc nh quan st ch ngha t bnhin i lu rng c s tch bit gia

quyn ch s hu v kim sot (Knight1921; Berle 1926; Berle and Means1932). Nu c s tch bit gia quynch s hu vi kim sot, th liu c mykhc bit gia hoc cc c phn c shu trc tip bi hng triu c nhn haybi "tt c" mi ngi thng qua nhnc? Nhng ngi ch trng ch nghax hi th trng gi rng khng c.

Phn tch cc hu qu ca s tch bitgia quyn ch s hu v quyn kim sot l mt ch chnh ca nghin cutrong kinh t hc thng tin. Phn ngnh [4]c tn "l thuyt ngi u thc- ngi il: principal-agent theory" c th c coil to nn mng cho vn khoa ca cc nm1950 nhn mnh n quyn t ca ccnh qun l (th d, March and Simon1958; Marris 1964). N xc nhn rng,

vi thng tin t , cc c ng ch cth c kim sot hn ch i vi cc nhqun l. Nhng nghin cu l thuyt ngthi v sau v st nhp v cc c chkim sot khc cng c thm kt lunlin quan n s t tr (t nht c tnh hnch) ca cc nh qun l. Nhng quan stl thuyt ny, c l, c xc nhn binhng din bin sau trong thi k amm st nhp v thn tnh cui cc nm1970 v cc nm 1980. i vi cc cngti ln, khng c "ngi ch duy nht" noti a ho gi tr k vng chit khu hinti ca li nhun, hoc thm ch ca th gidi hn. [5] Liu quyn s hu c tht squan trng? Hng BP c km hiu qu hnTexaco khng? [6] Hng ng st Qucgia Canada c km Canadian Pacific? [7]Liu c s cp ot li ch cng no ln

hn s cp ot ca Ross Johnson vnhng bn hu ca ng trong nhng cng ca RJR? [8]

V sao l thuyt hin i c th gi rng ch ngha x hi th trng l tcn thit hn nh trc y tng

L thuyt hin i, tuy vy, v thn trong nh gi tranh lun v ch nghax hi th trng so vi tho lun trc cth gi . Hai kt qu na ca l thuythin i c cc h qu m h hn.

Cnh tranhNh ti lu trc y, t nht mt

s ngi ch trng ch ngha x hi thtrng tin rng s la chn thch ngkhng phi l gia cc th trng cnhtranh v ch ngha x hi th trng, m lgia ch ngha t bn c quyn v chngha x hi th trng. [9] H tin rng

trong cc khu vc ln ca nn kinh t,cnh tranh l khng th c. Mt githit ct yu trong phn tch chng minhtnh hiu qu ca cc nn kinh t th trngl, mi x nghip u l ngi chp nhngi; x nghip phi hnh ng gi nh ntin rng n khng c nh hng g ln gin nhn c t bn hng hoc ln gi ntr cho cc yu t sn xut phi mua. Stng trng ca cc cng ti ln trong phnu ca th k hai mi dn nhiu nhkinh t hc n ngoi suy ra xu hng vhnh dung v mt nn kinh t trong mikhu vc ln - st thp, du, t, nhm, v.v.- c ch ng bi mt hoc nhiu nhtvi cng ti. L thuyt kinh t ng h cctin on: Cc cng ngh ko theo nhngkhon chi ph c nh ln. Nhng k thutt chc mi, nh c Alfred Sloan a

ra General Motors, c ngha rng ccch ph ngy cng tng gn vi cc doanhnghip qui m ln, pht sinh t thiu kimsot t chc, c th l hn ch. Vic thitlp cc th trng quc gia, v cc phngtin truyn thng quc gia qung cotrong cc th trng quc gia y, cung cpthm c s cho li tc theo qui m. Khngc ngun chnh gim li tc i vi xnghip, v mt s ngun ch yu tng litc, c th k vng rng mi ngnh cngnghip c thng tr bi mt, hoc nhiunht vi cng ti. [10]

Nh th s la chn i mt vi ccnn kinh t l (1) cho php ch ngha tbn c quyn gi vng, vi nhng mom trong phn b ngun lc (v hu nhkhng th trnh khi s tp trung quyn lcchnh tr) pht sinh; (2) c kim sot trc

tip ca chnh ph vi cc khu vc ny;hoc (3) c gng iu tit v kim sot sthc hin quyn lc c quyn, hoc bngcch x nh cc cng ti c quyn (vi ktqu mt hiu qu do khng khai thc ctnh kinh t theo qui m) hoc bng cchkim sot cc th on chng cnh tranh. tchnh ph dn ch no thy kh nng utin l c th chp nhn c. Hoa K cl nng n nht trong theo ui chin lcth ba. n gia th k, hn nm minm sau khi thng qua qui nh chng trustmang tnh bc ngot, nhiu ngnh cngnghip ct li ca M vn tp trung cao;ngay c thnh cng trong x nh StandardOil, c nhng tc ng m h, v cs tin tng rng Seven Sisters [by hngnh hn c tch ra] hot ng nhmt cartel, vi s cu kt v s hiu bit

v quyn li chung trong hn ch cnhtranh thay cho thng ng cng khai. Cclut chng trust dn n s tinh vi hntrong ng x chng cnh tranh! Nhng skin ny n gin cng c lng tin vochin lc th hai - s hu v kim sotca chnh ph. [11]

i chi vi xu hng tr tu ny, cita c th ngh l to h tr ln hn cho chngha x hi th trng, l s quc t honn kinh t ton cu. Cnh tranh b hn chbi qui m ca th trng, v do qui mca th trng thay i, nn tnh hiuqu ca cnh tranh cng vy. Nh th,trong khi vo cc nm 1960, GM, Ford, vChrysler khng ch th trng t M,ngy nay quyn lc th trng ca chng b xi mn, v chng phi i mt vicnh tranh hiu qu trong mi phn khc

ca th trng t cc nh sn xut NhtBn v Chu u. Trong khi th trng Mc th ch ln cho duy tr ba nh snxut ln, th trng ton cu li ln nmc duy tr nhiu hn nhiu.

Kinh t hc KeynesTrong tt c cc khuyt tt th trng

th mt tht bi, m tc ng lm xi mnlng tin ca cng chng vo cc qu trnhth trng, ln nht, l i suy thoi,th d ti t nht ca nhng khng hong cchu k gy tai ho cho cc nn kinh t thtrng sut cc th k ca ch ngha tbn. S tn ti v ko di ca nn thtnghip c th coi nh mt s bc b thuytphc m hnh tn c in: v trong m hnh, mi th trng, bao gm c th trnglao ng, u cn bng (clear).

L k l, cuc tranh lun v ch ngha

x hi th trng khng tp trung vocc cng trng tng i ca cc h thngla chn kh d, v bng chng lch s cgi tr hn ch: Mc d cc nn kinh t xhi ch ngha " gii quyt" vn thtnghip, li gii ca h c th lm chon b che y ch khng phi cng khai.Cc nn kinh t x hi ch ngha dngnh c th hin thng ging v tc tngtrng, du hiu ca thng ging trong hotng kinh t.

Tuy nhin vn cn c cc l do lthuyt ngh rng ch ngha x hi thtrng s gim nh vn c bn. Mttrong nhng ch trung tm trong cccng trnh kinh t v m tm du vt cacc cuc khng hong trong nhng "khuyttt iu phi". Ni toc ra l, khng cch lm vic bi v khng c cu cho u

ra ca cc x nghip, v khng c cu chou ra ca cc x nghip bi v ngi dnkhng c vic lm. Nu nn kinh t cm t tt bi m hnh Arrow-Debreu, nugi nh, th d, c mt tp ca cc thtrng, th cc khuyt tt iu phi ny cl s chng xut hin. Nhng ngi chtrng ch ngha x hi th trng lp lunrng c th khc phc c vn khuyttt iu phi, v nh th loi b s tn thtto ln v hiu qu kinh t gn vi cc cuckhng hong c chu k c trng ca ccnn kinh t th trng.

Mt ch khc gn y coi s sa stkinh t nh hu qu ca s bt hon hoca th trng vn cn tr kh nng cann kinh t dn tri v a dng ho riro. [12] Nh vy, nu cc x nghip cmthy gia tng ri ro, chng s gim mc

u t ca mnh. S gim bt dng tinmt c th buc gim u t, nu cc xnghip i mt vi phn phi tn dng vnu c cn tr trong vic ku gi vn dicc hnh thc khc (th d, qua vn cphn). Li na, ch ngha x hi thtrng, vi s kim sot u t trc tip,dng nh s lm gim nh nhng vn ny: n c l t u t mc cn thit duy tr ton dng lao ng.

Trong cc nm 1970 v u cc nm1980 c mt tuyn cng trnh trong kinht hc v m gi rng nhng mi lo ngikinh t v m ny khng quan trng lm.Cc nn kinh t iu chnh nhanh i vinhng xo ng. Xu hng trong cc ihc M khng a lch s kinh t vo nhmt phn ca mn hc kinh t tngcng s thin cn ca k c, dn nhiu

hc gi kinh t hc M i n kt lun rngcc cuc suy thoi l vn ca qukh - nu chng l cc vn khi .Nhng ng tic, suy thoi ln vo ucc nm 1980, suy thoi ca u cc nm1990, v s tht nghip dai dng mc cao ti Chu u a ra mt cnh bo thl cho nhng ngi tin rng tht nghipmang tnh chu k l chuyn ca qu kh.Nhng kinh nghim ny chuyn mtthng bo: C ci sai cn bn no vim hnh Arrow-Debreu. Gi nh m hnh ng, tht nghip s khng tn ti, v skh gii thch tnh d bin ng ca nnkinh t, cn c vo vai tr ca gi c tronghp thu cc c sc v cn c vo vai trca kho hng, tit kim, v cc th trngbo him trong vic lm m cho c cc xnghip ring l ln cc h gia nh khi

tc ng ca cc c sc.Nhng trong khi Keynes, cng nh

nhng nghin cu sau theo trng phiKeynes mi, cung cp s gii thch choc tht nghip ln tnh d bin ng cann kinh t - trong khi n c th nhn dngchnh xc ci g l sai vi m hnh Arrow-Debreu ci c th tnh n nhng quan stny - th mt thng ip khc ca Keynescng thy r rng: Nhng cn bnh kinh tv m ca ch ngha t bn l c th chatr c. Khng cn tin hnh nhng cicch cn bn trong h thng kinh t. Chcn chnh ph can thip chn lc. Theongha ny kinh t hc Keynes lm yung k s bin h cho ch ngha x hith trng.

D cho cc vn ny c quan trngn u, bn lun su v n s a ti ra

khi phm vi ca cun sch ny.Nhng nghi ng v tnh tho ng

ca nh l Lange-Lerner-Taylor: Visuy ngh s b

Cn nhc k, ti ng rng nhng phttrin trong l thuyt kinh t hin i, m ti tm tt - s tha nhn v tm quantrng ca (s thiu vng trong nn kinh tth trng mt tp ca) cc th trngk hn v ri ro, s tch bit ca quyn shu v kim sot, s bt hon ho cacnh tranh, v s ti din ca nhng thngging kinh t v tht nghip - phi dn tis nghi ng ln hn vi tnh hiu qu cacc qu trnh th trng.

Th m hu ht cc nh kinh t hcngy nay li biu hin mt s tin cy lnhn, ch khng t i, vo cc qu trnh thtrng so vi h c th c nm mi

nm trc. H, c bit, nghi ng tnh thong ca nh l Lange-Lerner-Taylor.Nhn xt nhn qu gi rng cc nn kinht x hi ch ngha khng ging ht ccnn kinh t t bn ch ngha, cn xa mith. M hnh ch ngha x hi th trngt c s cho nh l l sai lm nghimtrng.

Nhng lun im ca chng ti l,cng quan trng ngang nh nhn xt rngm hnh ca nn kinh t th trng - to cs khng ch cho nh l m c cc nhl cn bn ca kinh t hc phc li - l sailm nghim trng. Vi mt m hnh ti cann kinh t th trng v mt m hnh tica nn kinh t x hi ch ngha, khngngc nhin rng bt k v ging nhau bngoi ca s tng ng ca hai, nhiunht, c th ch l vn ngu nhin!

Hayek i li vi StiglitzPhn ln ca chng tip theo lin

quan ti vic gii thch v sao cc nh lca kinh t hc phc li tn c in chngni c my cho nhng ngi tin hnhla chn cc h thng kinh t kh d. Ktlun ny, v thm ch nhn mnh ca ti vl do cho kt lun ny, s bt hon hothng tin, c th xem ra quen thuc vinhiu bn c thng tho vi truyn thngo. Hayek lp lun mnh m rng mhnh thng tin hon ho n gin khngthu tm c vai tr ct li ca gi c vth trng trong truyn t v tng hpthng tin.

S bt ng ca ti khng phi vikhng nh ny, cng chng vi nhiu ktlun ca ng, nh tm quan trng ca khoch ho ca cc x nghip. Mi lo ngi

ca ti l quan tm kp: Th nht, bi vHayek (v nhng ngi theo ng) khng pht trin c cc m hnh hnhthc ca qu trnh th trng, khng c khnng nh gi nhng i hi lin quan ntnh hiu qu ca qu trnh , v th hai(v lin quan n) s thiu vng m hnhho nh vy, khng c kh nng cpn cc vn ct yu lin quan y, skt hp v thit k cc hot ng cng vt, bao gm nhng hnh thc kh d caiu tit ("nhng lut chi" kh d mchnh ph c th thit lp) v nhng uim ca cc chnh sch la chn kh dhng ti tp trung ho-phi tp trung ho.Nh Sanford Grossman v ti vitkhong mi lm nm trc.

Mc d cuc tranh lun [gia lange-Lerner-Taylor v Hayek] trc y c l

v tnh hiu qu thng tin ca cc cu trct chc kh d, cc m hnh trong cch thng phi hiu chnh vi thng tin mi khng c thit lp; thay vo tranh lun rng nu th trng gi l nhnhau, th phn b s ht nh nhau, v nhth, s so snh cc t chc kh d trthnh vn ging nh so snh chi phkhc bit pht sinh t cc hnh mu khcnhau ca lung thng tin, hoc tc hit khc nhau. (Grossman and Stiglitz 1976,252).

Chc chn, bt k m hnh n ginno u khng th thu tm tnh phc tpca cc vn thng tin ca nn kinh t.Khng m hnh n gin no c th thutm cc qu trnh theo cc nh chthch nghi vi hon cnh thay i. Chngta mc ri ro trong thit lp mt m hnh

n gin, vi mt tp n gin cc vn thng tin phi khc phc, qu trnh thtrng c th t ra thc hin kh tt, khitrong thc t, vi mt tp thc tin hnca cc vn thng tin, hiu sut ca nl km hn nhiu. (iu ngc li cng cth, tuy t c kh nng hn: th trng thchin km vi nhng vn n gin nhngthc hin tt trong cc vn phc tphn m n phi thch ng).

Nhng ngi ch trng theo truynthng o thng bo v s thiu vng mhnh hnh thc - v s thiu vng cc nhl hiu qu mt cch hnh thc tng ng:Nn kinh t l mt qu trnh hu c, quphc tp c th rt gn thnh cc mhnh hnh thc n gin. Cng vic cacc nh kinh t hc l m t qu trnh huc ny v nhn ra nhng loi chng

ngi no m s thiu vng, mt mt, cakt cu php l hoc, mt khc, s canthip thi qu ca chnh ph, c th gy ra.Nhng trong khi h c th khng phi,hoc thm ch khng mun, vin n tiuchun phc li chun ca tnh ti uPareto, th li c nhng ng mnh mangtnh chun tc trong tho lun ca h.Darwin c th ngh rng ng ch nthun m t qu trnh tin ho khi ngkhng nh ci dn n s sng cn ca cth thch hp nht, nhng nhng khng nhnh vy i hi mt nh ngha v "thchhp nht - the fittest" v v nghin cu cnbng chung, v v cc tnh cht ng hcca h thng. Ngy nay chng ta tha nhnrng qu trnh tin ho, di nhng honcnh a dng rng, c th khng c cctnh cht "hiu qu". [13]

V s thc rng th gii l phc tphn nhiu so vi bt k m hnh no mchng ta c th xy dng khng min chochng ta khi nhu cu kim nghim cc tng ca mnh bng s dng cc m hnhn gin v c th hiu c. Nu cc thtrng khng hot ng hiu qu di cciu kin l tng ho, th lm sao chngta c th tin c chng s hot ng hiuqu di nhng iu kin phc tp hn?Ch c th do lng sng o (v thc ra lvt qu lng tin)!

Chng trnh nghin cu m ti thamgia hn hai mi nm qua bt u xydng mt s m hnh n gin nh vy,nh gi xem cc qu trnh th trng hotng trong thu thp, chuyn ti, v x lcc loi thng tin a dng th no, trongcc bi cnh th trng a dng khc nhau.

Trong nm chng tip theo, ti s trnhby mt s kt qu nghin cu .

________________________________________[1]Ti s quay li ch chung ny

trong cun sch. y n gin ti munchun b trnh by: C qu nhiu nh kinht hc ngy nay gt b ch ngha x hi thtrng ngay lp tc, ni rng n "hinnhin" sai.

[2]Cng phi tn ti cc th trng chomi ri ro. Trong Chng 3 ti s tip tcvn v sao cc th trng k hn v riro khng tn ti, v s tho lun bao quthn nhng h qu ca vic khng c nhngth trng nh vy.

[3]Trong lp k hoch hng dn, ccx nghip khc nhau trong nn kinh t bocho chnh ph bit h s c k hoch ut v sn xut bao nhiu trong tng lai,

v nhu cu tng ng ca h v u voyu t l g. V nguyn tc, sau , chnhph c th dng thng tin ny -th d, thng bo cho cc x nghip rng s cmt s mt cn bng trong mt s thtrng tng lai, hoc, rng cn c vocc k hoch hin thi, cung v thp svt cu. cho k hoch hng dn hotng, cc x nghip phi tit l cc ngcu v yu t v cung v u ra ca h -tc l, h "c k hoch" lm g - tu thucvo gi c no c th xut hin trn thtrng. Hu ht cc x nghip, tt nhin,khng c cc k hoch vch ra r rng nhvy. Nhng c l l do cn bn hn chotht bi ca k hoch hng dn l ccx nghip n gin khng c khuyn khch tit l thng tin cn thit, ngay c nuh c.

[4]Vn khoa ny, ny sinh t cc bibo ca Ross (1973) v Stiglitz (1974), c rt nhiu. Cho mt tng quan ngn,xem Stiglitz (1989a).

[5]Thc vy, nh ti lu trong biging Tokyo (1972b) ca ti, do thiu mttp ca cc th trng, nhn chung skhng c s nht tr gia cc c ng linquan n mc tiu m cng ti phi theoui.

[6]Cho n gn y, a s c phn caBP (British Petroleum) do chnh ph Anhnm gi. Texaco, l mt cng ti du m tnhn M, ni ting trong ngnh du dokt hp tnh kiu ngo v bt ti qun l;khi Texaco thua kin hng t la mPennzoil kin, do a ra hng duGetty vi phm hp ng bn cng ti choPennzoil, Texaco chng my c a

chung.[7]Bng chng, cCaves and

Christensen (1980) cung cp, cho thy lkhng. (ng st Quc gia Canada dochnh ph s hu; Canadian Pacific lhng t nhn).

[8]RJR-Nabisco l mtconglomerate ln M, c bit n banu bi hai dng sn phm - thuc l doR.J. Reynolds bn, v cc loi bnh (m)do Nabisco sn xut (bao gm c nhngsn phm khc, nh Da Dole) - nhngcng ngy cng kht ting v phong cchsng ca cc nh qun l ca n, bao gmmt i ln cc my bay phn lc, cc nhngh v cc khu trt tuyt ca cng ti.Xem Barbarians at the gate [Nhng k thl cng] ca Bryan Burrough v JohnHelyar bit mt bin th ph bin v

chuyn thn tnh ny. C nhiu ti liu lthuyt v kinh nghim ngy cng tng tholun v xung t li ch gia cc nh qunl v cc c ng. Xem, th d, Morck,Shleifer, and Vishny (1989, 1990),Shleifer and Vishny (1986, 1989), vJensen (1986).

[9]Xem, Persky (1989).[10]Vn khoa l thuyt trong cui cc

nm 1920 v u cc nm 1930 phn nhmi quan tm ti li tc gia tng v tmquan trng ca cc chi ph chung. Xem, thd, Lewis (1928) v Clark (1923). Trongcc mi quan tm c bn cht ca cnbng. Xem, th d, Young (1928). Tnhng mi quan tm ny sinh ra l thuytcnh tranh khng hon ho. Trong khacnh ny, trong khi ng gp caChamberlins (1933) c th l c o

hn, cn ca Robinson (1933) lin quantrc tip hn n nhng vn ct li.

[11] C l ti phi nhc n mt thuytminh lp lun rng nhng bt hon ho cacnh tranh c t hu qu hn nh c hnh dung trc y - hc thuyt khnng tranh ot cho rng cnh tranh timnng l tt c ci cn m bo hiu qukinh t; thm ch vi mt x nghip, cc lich ca cnh tranh s c chuyn cho cckhch hng, bi v li nhun s c yxung bng khng. Nhng kho st k hnv cc th trng hot ng ra sao chra rng cnh tranh thm ch t vng chihn l cc nh kinh t hc ngh trcy: C rt nhiu chin lc m cc xnghip c th p dng (ngoi s cu ktcng khai) rn e s tham gia v hnch cnh tranh gia chng. Cnh tranh c

th b hn ch ngay c vi cc chi ph cnh, chi ph lng chm rt nh. Xem, thd, Stiglitz (1987g).

[12]V tng quan, xem Greenwald andStiglitz (1993) hoc Stiglitz (1992b).

[13]Do thiu mt th trng vn honho, th d, cc x nghip thy kh sng st- nhng ai bit rng trong cc hon cnhtng lai h s thnh vng nu h ch cth chu ng cho n khi - khng th ivay i li s thnh vng tng lai cah. Xem Stiglitz (1975a, 1992c). V tholun cc vn "hc hi", xem Bray andKreps (1987).

3. Ph phn nh lc bn th nht cakinh t hc phc li

Trong chng ny v chng tip theoti quay li cc nh l c bn ca kinh thc phc li. Trong chng ny ti lplun rng nh l c bn th nht ca kinht hc phc li - khng nh tnh hiu quca cc nn kinh t cnh tranh - l sai vcn bn. Hon ton ngc vi nh l y,cc nn kinh t cnh tranh hu nh khngbao gi hiu qu (trong ngha chnh xcc nh ngha di y). Chng tiptheo trnh by mt phn tch ph phntng t i vi nh l c bn th hai ca

kinh t hc phc li. Trong c hai chngti tp trung vo cc vn ny sinh tcc gi thit v thng tin hon ho v tpy ca cc th trng. Cc vn khc, nh cc vn lin i ti cc githit khc ca cc nh l ny nh s thiuvng ca thay i cng ngh ni sinh,c bn n trong cc chng sau.

nh l cn bn th nht khng nhrng mi nn kinh t cnh tranh u chiu qu Pareto. y l s th hin hini ca phng on v bn tay v hnh caAdam Smith:

Con ngi c nhu cu hu nh lin tcn s gip ca ng loi, v tht vdng i k vng ch vo lng nhn t cah. Anh ta chc s thnh cng hn nu cth khu gi tnh ch k ca h c licho mnh, v ch cho h thy rng lm cho

anh ta ci m anh ta yu cu h lm chnhl v mi li ring ca h Chng ta cba n khng phi l t lng nhn t cangi hng tht, ngi ct ru bia, hocngi lm bnh m, m l t s quan tmca h n li ch ring ca mnh. Chngta chm ch, khng phi vo lng nhn oca h m vo tnh ch k ca h, v ngbao gi ni vi h v nhng nhu cu ringca chng ta m v cc mi li ca h.

Smith tip tc m t t li dn ti lich x hi ra sao:

Anh ta ch mun li ring ca mnh, vanh ta trong trng hp ny nh trong baonhiu trng hp khc, c dn dt bimt bn tay v hnh thc y mt mcch khng phi l mt phn ch ca anhta. Cng chng phi l ti hn vi x hiv khng phi l mt phn ca ch .

Bng cch theo ui t li ring anh tathng thc y li ch ca x hi huhiu hn so vi khi anh ta ch thc yn. [1]

Chnh nh l phc li th nht to nntng cho lng tin ca chng ta vo cc nnkinh t th trng. Ging nh bt k nh lno, nhng kt lun ca n ph thuc votnh hiu lc ca cc gi thit. Kho st kcc gi thit, tuy vy, gi rng nh l c tnh tho ng hn ch i vi cc nnkinh t cng nghip hin i.

Cc nh l Greenwald-Stiglitz vtnh hiu qu ca cc th trng cnhtranh [2]

Thng l th khi lu cc gi thitno m mt tc gi nu bt, bng cch gncho chng cc nhn "gi thit A.1 A.10" v cc gi thit no l ngm nh,

bt lun c hay khng: cc gi thit ngmnh c trong mi m hnh, l cc githit c a ra mt cch tnh c, dngnh khng hn mt s nhc nh n cchdng thng thng, hoc l cc gi thitc bao hm trong cc nh ngha c bnno . nim rng cn bng th trngphi c c trng bi cu bng cung, thd, c a ra nh mt phn ca nhngha v cn bng trong m hnh cnhtranh chun. Ng rng phi l hin nhinnu cu khng bng cung, th s c cc lclng thay i, sao cho tnh trng khngphi l mt cn bng. [3] Cng trnh miy v cc nn kinh t vi thng tin khnghon ho ch ra rng kt lun lkhng ng; cn bng th trng cnh tranh[4] c th c c trng bi cu vtcung (nh trong cc m hnh Stiglitz-

Weiss 1981 v phn phi tn dng) hocbi cung vt cu (nh trong m hnhShapiro-Stiglitz 1984 v tht nghip vilng hiu qu). [5] Tng t m hnhcnh tranh chun bt u vi gi thitngm v mt h thng gi tuyn tnh (mtgi c nh cho mt n v hng cmua), trong khi by gi chng ta bit rngcc th trng cnh tranh vi thng tinkhng hon ho c c trng bi hthng gi phi tuyn tnh, trong , th d,c gim gi theo s lng. [6] Gi thitchun rng cn bng cnh tranh dn ti linhun bng khng cng c th c ch ral khng ng n trong cc m hnh vithng tin khng hon ho. [7]

Tm quan trng ca cc gi thitthng tin

S tht, rng c nhiu n nh vy cc

kt qu chun khng cn ng khi cc githit cc oan v thng tin hon ho cb i, nhn mnh n tm quan trng chung-v cho n tn mi y, cha c nhnra mt cch y - ca cc gi thitthng tin trong phn tch cn bng cnhtranh. Nhng lo ngi v cc gi thit ngmnh cng c tm quan trng ngang th ivi vn ngay sau- nh gi nhng cchkh d khc nhau ca t chc nn kinh t.nh l th nht ca kinh t hc phc lida trn c s gi thit rng c thng tinhon ho, hoc chnh xc hn, rng thngtin l c nh - v c bit khng b tcng bi bt k hnh ng ca bt k cnhn no, bt k gi no, hoc bt k bins no nh hng bi hnh ng tp thca cc c nhn trong th trng- v rngc mt tp y ca cc th trng ri

ro. H khi no cc iu kin ny khngtho mn th th trng l khng hiu quPareto hn ch; tc l, c nhng can thipca chnh ph c th ci thin phc li mtcch r rng. Nhng can thip ny tntrng nhng hn ch v cc th trng vchi ph thng tin (v marketing) ht nhnhng hn ch nh hng n kinh t tnhn. Thc vy can thip ca chnh ph cth t ra ng mong mi, ngay c nu chnhph c cc cng c rt hn ch, th d,chnh ph b hn ch i vi gi n gin(tuyn tnh) v can thip trn gi [8] ngu. Ngoi ra, bn cht (v thm ch ln) ca nhng can thip ng mong c thc quan h vi cc tham s th trng cth quan st c, nh cc nhm dn ckhc nhau phn ng vi nhng thay i vlng v gi ra sao. [9]

Theo mt ngha, thnh t v i caDebreu v Arrow l tm ra mt tp hunh duy nht ca cc gi thit theo don v bn tay v hnh ca Adam Smithl ng. [10] Thc ra, c mt vi trnghp c bit khc trong th trng cth c hiu qu Pareto hn ch. Th d,thiu cc th trng ri ro s khng c hqu no nu mi ngi u ht nh nhauv i mt vi cc c sc y ht nhau, saocho ngay c nu gi nh c cc th trngri ro, th s chng c trao i no trong; [11] hoc nu gi nh mi hng ho domi c nhn tiu dng u c th quan stc, th cc nn kinh t trong c himho o c vn s c hiu qu Pareto hnch. [12] (Kinh t hc phc li ca ccnn kinh t vi him ho o c cPrescott v Towsend kho st t m nm

1980. Nhng khc bit trong kt lun giaGreenwald-Stiglitz v Prescott-Towsendc cho l do nhng ngi sau tp trungvo trng hp c bit ny m Arnott vStiglitz nm 1985 cng nh Greenwald vStiglitz chng minh l c hiu qu).

Nhng tc ng ngoi lai trong shin hu ca thng tin khng hon hov cc th trng khng y

S thu hiu c bn ca Greenwald vStiglitz l khi cc th trng khng y v thng tin khng hon ho, th cc hnhng ca cc c nhn c nh hng gingnh nh hng ngoi lai ln nhng ngikhc, m chng khng c tnh n.(Nhng tc ng ngoi lai nhn chungging nhng tc ng ngoi lai ca "khquyn" ch mc ca chng ph thucvo hot ng ca tt c mi ngi cng

nhau). Mt s th d gip minh ho vn l g:

1. Cc th trng ri ro khng y .Gi s rng c nhiu trng thi t nhin,nhng ch c mt ti sn ri ro, cc cyto. S cy to c trng xc nh (mtcch ngu nhin) s qu to sn xut ratrong nm tip theo, v s ny n lt nli xc nh gi v tnh sinh li ca vics hu mt cy to, trong mi trng thi tnhin. Khi cc c nhn trng nhiu tohn, phn b xc sut ca li tc t trngto thay i, v v cc cy to l cckhon u t c ri ro duy nht, theo githit, c nh l mt ti sn (phn b xcsut c) c thay th bng mt ci mi.Mi nh u t tt nhin coi phn b xcsut li tc l cho trc, ngay c tuy n cthay i khi nhiu cy to c trng hn.

Tc ng ca hnh ng ca tng c nhnln phn b xc sut nh th c th xemnh mt tc ng ngoi lai. [13]

2. Cht lng lao ng thay i(chn lc c hi). Hy xt vn thng tinkhng hon ho v cht lng ca ngilao ng. Cc cng ti c th bit chtlng trung bnh ca nhn cng c chotrong mt hi trng thu nhn cng. Hcng c th bit cht lng b nhhng ra sao bi lng c tr. [14]Cu ca h v lao ng, mi mc lng,s ph thuc vo bin s cht lng ny.Mt khc, mi ngi lao ng, d chtlng cao hay thp, li khng tnh n tcng ca quyt nh ca mnh lin quann lng cung lao ng ln cht lnglao ng trung bnh (v mt cch tngng ln cu lao ng). Thc ra, nu nhng

ngi lao ng c cht lng thp quytnh cung cp nhiu lao ng hn, bt kmc lng cho trc no, n s h thpli nhun ca hng. Cc hnh ng ca hs c nh hng ngoi lai n cc hng.Theo cng cch, l d i vi chnh ph tc ng n hn hp cht lng, thd, bng cch nh thu hay bao cp cchng ho c nh hng khc nhau ln cunglao ng cht lng thp v cc c nhnc nng lc cao. [15]

3. Cc vn khuyn khch (himho o c). Cc c nhn mua bo himbi v h khng a ri ro. Nhng bo himc ngha l h khng phi chu y cchu qu ca cc hnh ng ca h: Cckhuyn khch ca h loi tr s kinc bo him b yu i. Mi c nhn coiph bo him l cho trc. Tt nhin, nu

tt c mi ngi t cn thn hn, th skin c bo him s xy ra thngxuyn hn, v ph s tng ln.

Th d ny cng ch ra chnh ph c them li mt s ci thin Pareto ra sao.Bng cch nh thu hay bao cp cc mthng khc nhau, chnh ph c th khuynkhch cc c nhn cn trng hn. Gi strng hp c bo him l thit hi dochy gy ra, v mt nguyn nhn chnh gychy l ht thuc trn ging. Ht thuctrn ging l c bit nguy him nungi ht cng ung qu nhiu. C thtng tng, trn nguyn tc, mt hpng bo him c iu kin i hi ngic bo him khng c ht thuc trnging sau khi ung, nhng iu ny khthc thi. (Cng ti bo him c th lp ccTV theo di trong mi phng ng, nhng

mt s ngi c th coi iu ny nh xmphm ring t c nhn). Nhng bng cchnh thu thuc l v ru bia, chnh phc th ngn bt vic ht thuc v ungru ni chung, v nh kt qu ph, cnglm gim bt ht thuc trn ging sau khiung. t nht vi cc khon thu nh, phcli tng thm t gim "him ho o c"c th nhiu hn khon mt mt phc lit nhng mo m (mt trng) trong thiquen tiu dng do thu gy ra. [16] Chcphi r l cc khon thu v bao cp phic nh sao cho chng khuyn khch scn trng, th d, tr cp cc mt hng bsung cho chm sc cn thn, v nh thunhng mt hng thay th. Cc thu sut tiu c nh ra sao cho ti bin, li chdo s cn trng mang li cn bng vikhon mt trng bin. C hai i lng ny

c th c tnh ra t cc i lng c thquan st c (th d, cc co gin gi[ring v cho] c b tr ca cu vcc co gin ca "cn trng" i vi ccgi khc nhau). Nh vy, trong khi cchng bo him nh nc v t nhn khngc thng tin cn thit ngn nga himho o c - chng khng th trc tipkim sot cc hnh ng- th chnh ph lic cc cng c gim nh tc ng cahim ho o c v c thng tin cn thit dng cc cng c . [17]

Sc mnh ca chnh phTh d ny cng minh ho cho nhng

nng lc m chnh ph c th c, cn khuvc t nhn th khng. C mt "nh l dngian" [18] (hoc ci c th gi l mt nhl dn gian, gi nh n ng) pht biurng bt k ci g chnh ph c th lm, th

khu vc t nhn cng c th lm nh thhoc tt hn: Nhng u th c cho lca chnh ph ch ny sinh t nhng sosnh "khng cng bng", th d, mt chnhph vi thng tin khng mt chi ph c thci thin phn b th trng, trong khi ccth trng phi i mt vi thng tin tnchi ph. loi tr ph phn ny m titp trung vo khi nim v tnh hiu quPareto hn ch.

Nhng vn vn cn c cp:Chnh ph khc cc t chc kinh t khc rasao? V sao n c th lm nhng th mcc t chc khc khng th? y l vn c trnh by trong cun sch ca ti,Vai tr kinh t ca Nh nc - TheEconomic Role of the State, ti lplun rng sc mnh, nng lc cng chca chnh ph (kt hp vi tnh cht thnh

vin ph qut ca n) cho n nhng u thring bit (v mi lo ngi v lm dng ccquyn hn gy ra nhng rng buc tothnh nhng bt li ring). Nh vy chnhph c th cm sn xut thuc l - khng tnhn no hay nhm c nhn no c th lmiu ny. (Tt nhin, thc thi vic cmon ny, chnh ph phi c nng lc theo di sn xut thuc l. Nu gi nhkhng c tnh kinh t theo qui m trong snxut, th c th kh cho chnh ph thcthi cm on ny. Nhng vi tnh kinh ttheo qui m ng k, nu chnh ph khngth thc thi cm on, n c th t nhttng chi ph thuc l ln ng k). Tngt, chnh ph c th p t thu ln snxut mi loi thuc l. C th c kh nngquan st, v do c th nh thu, snxut thuc l ngay c khi khng th quan

st cc mc tiu th c th (khng th theodi trao i th cp). Khng hng bohim t nhn hoc cng ti thu h bo himno c th "buc" tt c cc cng ti thucl tr thu trn sn lng ca h. Gi srng chng t lt h, bng cch tr mtkhon ph thuc vo khon gia tng gica h. Khi mt cng ti mi c th tinvo, t gi bt mt cht, chim ht khchhng ca h, v kim li. y ch l mtminh ho cho s tht rng chnh ph quthc c nhng nng lc m khu vc tnhn khng c, nhng quyn lc m trongmt s trng hp nht nh (nu cdng kho) c th to ra ci thin Pareto.(V cc th d khc, xem Stiglitz 1989f,1991c).

Vi lu v din gii cc nh lGreenwald-Stiglitz

Cc nh l Greenwald-Stiglitz v ccnh l lin quan c ba din gii: Th nht,nh chng ta thy, trong cc trng hpnht nh chng cung cp nhng hnh thcc nhn din r v can thip ca chnhph mang li ci thin phc li. Th hai,chng gi rng c th khng c kh nngphi tp trung mt cch c hiu qu, theocch nh cc nh l c bn ca kinh thc phc li gi . Ti s quay li ch ny mun hn trong chng ny. Thba, v c l quan trng nht, chng loi biu phng on ph bin rng cc thtrng nht thit l cch hu hiu nht phn b ngun lc. Phi nhc li, chng cnh l chung no lm c s cho kt lun. (Tt nhin c cc c s khc i nkt lun , mt im m ti s cpngay).

Trong kha cnh ny cc nh lGreenwald-Stiglitz trc ht khng ccoi l c s cho vic vch ra can thipca chnh ph. Mt trong nhng l dochng khng to c s cho qui nh canthip l, lm nh vy s i hi mt mhnh hnh thc v chi tit hn v chnh ph.Khi nh l trung tm ca kinh t hc khngnh rng khng chnh ph no - bt k nnhn t n u, bt k n duy l n u -c th lm tt hn cht no so vi thtrng, chng ta t cn n mt l thuyt vchnh ph: n ch c th lm ti t hn.Nhng cc nh l Greenwald-Stiglitzkhng nh rng c mt vai tr tim nngcho chnh ph. Liu chnh ph c nn canthip v can thip th no l mt vn ti s quay li sau. (C l, do cc chnhph l cc nh ch chnh tr, cu tr li s

ph thuc mt phn vo hnh thc m ccnh ch ny c hoc c th c. Cc nhl cho chng ta bit, nu chnh ph quytnh can thip thng qua, th d, thu vtr cp, cc tham s ch cht da trn thu sut v t l tr cp phi ph thucvo).

Cc l do khc v sao cc nn kinh tth trng vi thng tin khng hon hoc th khng c hiu qu Pareto

Trong khi cc nh l Greenwald-Stiglitz a ra lp lun mnh m nht bcb nh l cn bn th nht ca kinh t hcphc li, nhiu kt qu khc ca h thuytthng tin a ra nhng ph phn cn bnngang nh th. Ti mun lu ch n bakt qu, hai trong s lin quan n cchthc nhng cn nhc l thuyt thng tin dnn kt lun rng cc gi thit khc ca m

hnh cnh tranh chun (m hnh to c scho nh l cn bn ca kinh t hc phcli) s khng c tho mn. Danh mcdi y khng phi l ton din. Ti ctp trung vo ci ti xem l cc gi thitkinh t ch yu. [19]

Tnh khng y ca cc thtrng

Chng ta nhn mnh chng 2n tm quan trng trong h thuyt cnhtranh chun - v tnh phi hin thc- ca githit rng c mt tp y ca cc thtrng, bao gm mt tp ca cc thtrng ri ro v k hn.

Cc chi ph giao dchTnh y ca th trng t n c th

c gii thch bng cc chi ph giao dch,mt thnh phn quan trng ca chng lcc chi ph thng tin. C cc chi ph lin

quan n thit lp th trng. Gi nh nuc cc th trng cho mi trong hng triuhng ho, mi trong hng t cc tnh hungtu thuc, mi trong v s cc thi imtng lai, th qu nhiu ngun lc ca xhi b ht vo vic t chc cc giao dchny n mc chng cn my m mua vbn trn mi trong nhng th trng ny!

Mt khi chng ta tha nhn c v ss kin nh hng n chng ta, chng tacng nhn l khng th c thm ch mt tpy ca cc th trng ri ro (bo himmi tnh hung ri ro). Mi x nghip bnh hng khng ch bi cc s kin tcng n ngnh m c bi cc s kin cbit - bnh tt ca gim c, s hng hcca mt chic my, vic b i ca mtngi bn hng ch cht. Bn thn xnghip c th mua bo him cho nhiu ri

ro m n i mt, nh bo him khi xe tica n gp tai nn hoc cho chy nh my,nhng hu ht cc ri ro m n phi imt khng th c bo him. Quan nimrng c cc th trng cho mi trongnhng ri ro ny l khng th tin c.

S Khng nht qun gia cc githit v "Cc th trng y " v "ccth trng cnh tranh"

Ht nh s chiu rt ln ca "cc trngthi t nhin" lm cho hin nhin rng mttp y ca cc chng khon n ginl khng th tn ti, cng th do s chiurt ln ca khng gian cc sn phm lmcho r rng rng mt tp y ca ccth trng cho cc mt hng khng th tnti, mt khi chng ta nh li rng cc snphm c nh ngha bi mt c t y ca cc c trng ca chng: Cc sn

phm c cht lng khc nhau c coi lcc mt hng khc nhau, v cc sn phmc giao cc thi im v cc aim khc nhau c coi l cc mt hngkhc nhau. tng ca Arrow v Debreucoi cc mt hng ti cc thi im v cctrng thi t nhin khc nhau nh cc mthng khc nhau xem ra ging nh mt ththut ton hc kho lo, cho php m rngm hnh chun ti mt di mi, rng hnca cc vn , nhng khi kho st k hnth linh hn c s ca m hnh mt hiulc: Hoc n gin khng th tn ti mttp y ca cc th trng (gi nh thth phi c mt th trng cnh tranh honho cho vic giao mt chic my c cim k thut chi tit n mt nh my timt ngy nht nh vo mt gi c th)hoc, nu gi nh tn ti mt tp cc th

trng, th kh c th hnh dung mi thtrng nh mt th trng cnh tranh"hon ho" c (tc l c rt nhiu nhbun c bn mua v bn bn sao chomi thng gia tin rng mnh c nh hngkhng ng k ln gi). Tt yu, cc thtrng hn phi lo to v cnh tranhkhng hon ho. [20] Hy xt, th d, thtrng lao ng. Mi c nhn l khc bit,theo v s cch. Mt tp y ca ccth trng s bt phi c th trng khcnhau cho mi loi lao ng - mt thtrng cho lao ng ca Joe Stiglitz, thtrng ny khc vi th trng cho laong ca Paul Samuelson, ci n lt nli khc th trng cho cc th ng nc,ci n lt n li khc vi th trng cholao ng khng c k nng, vn vn. Nuchng ta thn trng trong nh ngha cc th

trng cho cc mt hng ng u (laong ca Joe Stiglitz c tin hnh timt ngy, trong mt trng thi, ti mta im c th), th ch c mt thng giaduy nht mi bn bn v bn mua (JoeStiglitz). Nu chng ta m rng cc thtrng bao trm tt c cc nh kinh thc l thuyt, th hin nhin c cnh tranhhn. Nhng chng ta phi t b cc githit r