Incen%ve  Strategies  for  Minori%es  

Results  of  an  Experiment  Using  Combined  Condi7onal  and  Uncondi7onal  Cash  Incen7ves  

     5th  Conference  of  the  European  Survey  Research  Associa7on  (ESRA)  

Ljubljana,  Slovenia,  July  15-­‐19,  2013  Patrick Fick, patrick.fick@uni-konstanz.de Claudia Diehl, claudia.diehl@uni-konstanz.de University of Konstanz, Germany

 

Outline

1.  Research on ethnic minorities in Germany

2.  Prior findings 2.1 Survey participation in general

2.2 Survey participation of specific groups

3.  The mechanisms of incentives 3.1 Unconditional incentives 3.2 Conditional incentives

3.3 Double incentive strategy

4.  Methods

5.  Results 5.1 Effects on response rate

5.2 Effects on data quality

6.  Summary

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1. Research on ethnic minorities in Germany

•  surveying immigrants is challenging

•  immigrant surveys: sample from telephone directory: –  telephone survey based on name-based selection (onomastics) (Haberfield

et al. 2011)

à inaccuracy of onomastic driven sampling sample from official resident register: –  face-to-face survey

–  bilingual interviewers often necessary (Blohm/Diehl 2001; Baykara-Krumme 2010)

à effective in terms of response rates à very expensive

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1. Research on ethnic minorities in Germany

sample from official resident register: –  self-administered survey via mail, internet, or telephone (after received

phone number on postcard)

à  low response rates, e.g. of mail surveys (Aust/Schröder 2009)

à  inexpensive method and relative short field time (Schnell 2012)

à  increases financial leeway to invest in -  multilingual survey material -  tailored incentive strategies

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2. Prior findings

2.1 Survey participation in general •  incentives well-known instrument to increase response rates (Wotruba

1966; Church 1993; Singer et al. 1999; Schnell 2012)

•  monetary incentives better than non-monetary (e.g. pens, key chains, prize draw) (Paolillo/Lorenzi 1984; Warriner et al. 1996; Edwards et al. 2002)

•  unconditional incentives better compared to conditional incentives (Church 1993; Singer et al. 1999; Diekmann/Jann 2001; Becker et al. 2007)

•  mixed evidence that higher amount of incentives lead to higher response rates –  e.g. minor and n.s. differences between unconditional payment of $1, $5, and

$10 (Bolstein/James 1992)

–  linear increase in response rate (¢1  up to $100) (Yu/Cooper 1983; Singer et al. 1999; Jobber et al. 2004)

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2. Prior findings

2.2 Survey participation of specific groups •  net sample comparisons:

•  no differences (Shettle/Mooney 1999; James/Bolstein 1990) •  less educated individuals overrepresented when incentives used (Stadtmüller 2009)

à which final sample is the unbiased one?

•  gross sample comparisons:

•  reduced bias in terms of sex, marital status, and wealth if incentives used (Goyder 1994; Barón et al. 2008)

•  scarce information whether incentives reduce nonresponse bias of immigrants (Feskens et al. 2008)

à  rather positive effects of incentives in terms of nonresponse bias à  higher participation of individuals from groups that otherwise tend to

be underrepresented in final sample

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3. Mechanisms of incentives

Why participate in a survey without material incentive?

•  subjective expected utility of participation must exceed that of non-participation (Esser 1986)

•  benefits of participation: –  first contact establishes weak form of reciprocity (Goyder 1960) –  participation as voluntary service fulfils norm of reciprocity (Dillman 1978; Arzheimer/Klein

1998)

à  this relatively low benefit based on intrinsic motivation or reciprocity can hardly be increased (and might differ by groups)

•  costs of non-participation: –  just psychological: violation of “norms of politeness” (Esser 1986)

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3. Mechanisms of incentives

3.1 Unconditional incentives (pre-paid) •  attempt to increase the costs of non-participation

–  unconditional incentives as “the gift” to reinforce a sense of commitment to a fair equivalent (Dillman 2000)

–  incentive not compensation for the effort, but a symbolic act à unconditional incentive makes non-participation more expensive

–  but: a too large gift destroys reciprocity and generates reactance à nonresponse is the only possible action of the individual to regain

control of the situation

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3. Mechanisms of incentives

3.1 Unconditional incentives (pre-paid) •  unconditional incentives twofold waste of resources:

–  investment in already willing participants

–  investment in persistent deniers

à conditional incentives seem to be the rational choice, but obviously they are not effective

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3. Mechanisms of incentives

3.2 Conditional incentives (post-paid)

•  conditional incentives increase the benefit of participation

•  problems: –  interview situation already associated with uncertainty (Esser 1986) –  incentive just another element of uncertainty, namely about

whether it is really given –  even a high incentive might only increase potentially expectable

benefit but does not reduce uncertainty

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3. Mechanisms of incentives

3.3 Double incentive strategy

•  increasing costs of non-participation and benefit of participation: –  unconditional part increases costs of non-participation by strengthen reciprocity

à „symbol of trust“ (Dillman 1978)

–  reduced uncertainty basis for conditional part that increases the benefit of participation

additional benefit of participation…

additional costs of non-participation…

…compared to intrinsically motivated participation

unconditional incentive 0 + conditional incentive (+)1 0 double incentive strategy + +

1Only if there is enough confidence in the actual payment of conditional incentive

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3. Mechanisms of incentives

Expectations 1. unconditional incentive à higher response rate compared to control group

2. high vs. low unconditional incentive à no difference

3. double incentive strategy à higher response rate compared to

unconditional incentive only

4. increase of conditional incentive à higher response rate in double incentive strategy

5. use of incentives à lower overrepresentation of wealthier individuals

6. use of incentives à lower overrepresentation of immigrants with strong identification with receiving country

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4. Methods

•  pilot study “Deutsche/r bleiben?” (Stay German citizen?), co-financed by University of Goettingen, Germany

•  sample of 500 German-Turkish dual citizens in seven German cities (Augsburg, Bielefeld, Bremen, Bremerhaven, Dortmund, Düsseldorf, Hannover)

•  quantitative survey (approx. 15 minutes) of young “optionspflichtige” (liable to option) immigrants born between 1990 and 1993

•  mixed mode design: participants had the choice between PAPI, CAWI, CATI

•  field work: June till August 2011

•  substantive (Diehl/Fick 2012) and methodological research question à

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4. Methods

•  methodological research questions: test possibility to identify the special population in official resident register, effects of different incentive strategies and subgroup-specific differences in the results

Experiment with five different incentive conditions

1. Control group No Incentive

2. Unconditional incentive (5 €) 5 € pre-paid enclosed in cover letter

3. Unconditional incentive (10 €) 10 € pre-paid enclosed in cover letter

4. Double incentive strategy (5 + 5 €) 5 € pre-paid enclosed in cover letter additional 5 € as promised “thank you” after participation

5. Double incentive strategy (5 + 10 €)

5 € pre-paid enclosed in cover letter additional 10 € as promised “thank you” after participation

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4. Methods

•  data enrichment using geodata (microm) advantages of data enrichment: •  at least some information for participants and non-participants •  aggregated information based on street segments with an average of

130 households

•  information about –  buying power of individuals’ street segment –  proportion of foreigners in individuals’ street segment

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5. Results

5.1 Effect on response rate

failure function:

total response rate: 55.5 % minimum: 37.0 % maximum: 66.3 %

66.3 % 62.9 %

56.8 % 55.2 %

37.0 %

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5. Results

5.1 Effects on response rate

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•  incentives lead to higher response rates •  no change if unconditional incentive is increased •  higher response rates using double incentives (n.s) •  no real change if conditional incentive part is increased

5. Results

5.2 Effects on data quality

•  gross-net sample comparison:

•  nonresponse bias of participants from poorer areas in no incentive condition (n.s.) •  no bias regarding proportion of foreigners •  higher participation of women in control group

à nonresponse bias lower if incentives used 18

5. Results

5.2 Effects on data quality

•  selected items in final sample:

•  less high school graduates in double incentive groups •  only little evidence for overrepresentation of individuals strongly identifying as German •  weak but rather positive effect of incentives on data quality

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6. Summary

•  self-administered interviews inexpensive alternative for immigrant surveys à  increase financial leeway to invest in tailored incentive strategies

•  double incentive strategy as combination of unconditional and conditional incentives… …takes into account the well-known positive effect of unconditional gifts …reduces the twofold waste of resources

•  logic of double incentive strategy: simultaneously increase…

…costs of non-participation (strengthen norm of reciprocity) …trust in the integrity of conditional incentive payment …benefit of participation (by promising a small “thank-you incentive”)

à  higher response rates

à  data quality seems to be affected rather in a positive way

à  incentive might help to get those demographic groups involved in surveys, known as hard to reach when just appealing on intrinsic motivation

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Patrick Fick, patrick.fick@uni-konstanz.de Claudia Diehl, claudia.diehl@uni-konstanz.de University of Konstanz, Germany

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