Understanding and combating nonresponse

Michel Philippens (KU Leuven)

Achim Koch (ZUMA, Mannheim)

Measuring attitudes and values in Europe:

The contribution of the European Social Survey

Brussels, 25-26 November 2003

Types of nonresponse

Non-contacts Refusals Others: illness / language problems

Effects of nonresponse

Reduction in final sample size (Potentially) nonresponse bias Increase in costs

Response rate target in ESS: 70 percent

Dealing with the issue of nonresponse in the ESS

Specification of a high target response ratetarget response rate /insisting on certain fieldwork proceduresfieldwork procedures

High quality survey organisationssurvey organisations should be selected /high response rates as a contractual obligationcontractual obligation

Close monitoringmonitoring of progress during fieldwork period /fortnightly reportsreports on response

Standardized documentation Standardized documentation of fieldwork /data on the aggregate aggregate and on the individual levelindividual level

Type of survey organisationBasic information on fieldwork - 1

Mode of interviewing: PAPI vs. CAPIBasic information on fieldwork - 2

Basic information on fieldwork - 3

Length of fieldwork period

Average length: 106 days

60 days or less: 3 countriesHungary (28) Slovenia (44) Greece (45)

61 - 120 days: 8 countriesDenmark (66) Poland (80) Sweden (88) Finland (92) Israel (92) Spain (93) Czech Republic (105) Portugal (116)

121 days or more: 8 countriesIreland (122) Luxembourg (122) Norway (123) United Kingdom (133) Switzerland (152) Italy (168) Netherlands (176) Germany (177)

Basic information on fieldwork – 4

Costs per interview

EstimateBlueprint:105 Euro(excl. VAT)

Informationfrom contracts:125 Euro(incl. VAT)

100

200

300

0

Sweden 262

Netherlands 229 Norway 223

United Kingdom 179 Denmark 176

Switzerland 171 Germany 156

Spain 125

Italy 63

Portugal 45 Slovenia 45

Poland 28 Czech Republic 27

Hungary 18

No information available:Finland, Greece, Ireland,Israel, Luxembourg

(in Euro, including VAT)

Fieldwork outcomes – 1

Achieved number of interviews

13 countries meeting the sample size requirement:Germany (2995) Greece (2566) Israel (2499) Netherlands (2364)Poland (2110) United Kingdom (2052) Ireland (2046)Switzerland (2041) Norway (2036) Finland (2000) Sweden (1999)Luxembourg* (1553) Slovenia* (1519)

6 countries not meeting the sample size requirement:• Because of budgetary constraints

Spain (1729) Hungary (1685) Portugal (1511) Denmark (1506)

• Because of low response ratesCzech Republic (1360) Italy (1207)

*Population of less than 2 million

Fieldwork outcomes – 2

Achieved response rates (in %)

50

60

70

80

40

30

Greece 80.0

Finland 73.2Poland 73.2

Israel 71.0Slovenia 70.5 Hungary 69.9Sweden 69.5Portugal 68.8

Netherlands 67.9Denmark 67.6Norway 65.0Ireland 64.5

Germany 57.1United Kingdom 55.5

Spain 53.2

Luxembourg 43.9Italy 43.7

Czech Republic 43.3

Switzerland 33.5