Extending the Random-Utility-Based Multi-Regional Input-Output Model (RUBMRIO) to the National Level

Dr. Kara KockelmanDr. Avinash UnnikrishnanSiva Karthik Kakaraparthi

The RUBMRIO Model

•Combines three distinct models: Input-output for production Logit model of input origins & modes Traffic assignment

• Recognizes: 18 economic sectors 3,109 U.S. counties Nation’s top 34 Ports Two modes: highway & rail

Industry Sectors1 Agriculture, Forestry, Fishing & Hunting 2 Mining 3 Construction 4 Food Manufacturing 5 Chemicals Manufacturing 6 Primary Metals Manufacturing 7 Fabricated Metals Manufacturing 8 Machinery Manufacturing 9 Electronic & Electric Equipment 10 Transportation Equipment 11 Other Durable & Non-Durable Manufacturing 12 Transportation, Communications & Utilities 13 Wholesale Trade 14 Retail Trade 15 FIRE (Finance, Insurance & Real Estate) 16 Service 17 Households 18 Government

The RUBMRIO Model (2)Inputs: Foreign Exports, Domestic Exports, Distances

Utility of purchasing commodity m from zone i

and transporting it to zone j, k, s

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Flow of m from zone j to export zone k, and other state s

Consumption of m in zone j

Production of m in zone i

Flow of m as an intermediate input from zone i to zone j

Average input cost for commodity m in zone j

Price of m in zone j

Trade Equilibrium?

Equilibrium Trade Flows

No

Yes

Data Sets

• Imports & Exports for nation’s top 44 ports available at USATradeOnline.gov.

• Top 34 ports, each exporting >$100 million/yr., were selected from 44 available.

• Caliper Corp. provided US highway network.

• Rail network obtained from Census 2000.

• Inter-county & county-to-port shortest paths by road & rail computed using TransCAD.

Other Data Sources

Data Sources

Logit Trade Coef. •1997 CFS

Truck Trips •1997 CFS

•Vehicle Inventory & Use Survey

Work Trips •1997 IMPLAN Data

•2000 Census Commute Data

Shop Trips •1990 Household Expenditures (BEA)

•Nationwide Personal Transportation Survey (NPTS)

•Austin Travel Survey of Households

Export Ports

List of Ports

1) Baltimore, MD2) Boston, MA3) Buffalo, NY4) Charleston, NC5) Chicago, IL6) Cleveland, OH7) Columbia-Snakes, OR8) Dallas-Fort Worth, TX9) Detroit, MI10) Duluth, MN11) El Paso, TX12) Great Falls, MT13) Houston, TX14) Laredo, TX15) Los Angeles, CA16) Miami, FL17) Minneapolis, MN

18) Mobile, AL19) New Orleans, LA20) New York, NY21) Nogales, AZ22) Norfolk, VI23) Ogdensburg, NY24) Pembina, ND25) Philadelphia, PN26) Port Arthur, TX27) Portland, OR28) San Diego, CA29) San Francisco, CA30) Savannah, GA31) Seattle, WA32) St. Albans, VT33) Tampa, FL34) Washington, D.C.

Total Exports (Million $)

US Highway Network

Network with County Centroids

US Rail Network

Road & Rail Network Details

Highway Network

• 359,328 links & 136,930 nodes (+3,109 CCs)

• Presently streamlining network assignment code (in C++) to run efficiently on such a large network.

Rail Network

• 156,172 links & 119,176 nodes

• 100-mile connectivity distance imposed.

Traffic Assignment

• Vehicle Trips due to economic flows… Truck & Rail Trips, Work trips & Shop

trips

• Highway network assignment based on 1-hour user equilibrium procedure:

• Production costs (& thus input prices) updated based on updated/congested travel times.

ijijijij TTripsPCEWRKTripsSHTripsPEAKVeh 08.020.005.0

Code Progress

• All Windows functions modified to generic C++ functions.

• RUBMRIO code now runs on Windows & Linux.

• RUBMRIO runs for Texas network (254 counties) on standard desktop.

• Texas Advanced Computing Center’s supercomputers will be used to run national applications (3,109 counties).

Code Progress (2)

• More efficiently coded to reduce memory allocations (rather than defining new arrays).

• Original twelve 3-D arrays of 183M units each Memory alloc. = 183M × 8 (double) bytes

= 1.4 GB of space per array.

• Code streamlined to now use only three arrays of the same size.

• 68% reduction in RAM use.

Example Results: Texas Application

Year 2020Year 2010

Example Results (2)

Variations in Intra-County Trade

Counties close to high-producers exhibit greatest % reductions, as they increase trade to those counties.

Coming Work

• Memory-efficient traffic assignment code is necessary to recognize network congestion for trade-cost implications.

• Once assignment code is complete, trade flows between all U.S. counties will be modeled.

• Case studies include impact of network improvements & disruptions on trade flows, impacts of growing export demands & shifts in commodity types demanded, & effects of system management (e.g., pricing).

Thank You!

Questions & Suggestions?

RUBMRIO Papers available at www.ce.utexas.edu/prof/kockelman/home.html