Download This Paper Open PDF in Browser

Placebo Statements in List Experiments

12 Pages Posted: 9 May 2017 Last revised: 10 May 2017

Kai Ostwald

University of British Columbia (UBC)

Guillem Riambau

National University of Singapore (NUS) - Yale-NUS College

Date Written: May 9, 2017

Abstract

List experiments are a widely used survey technique for estimating the prevalence of socially sensitive attitudes or behaviors. This paper shows a potential vulnerability in their design: in a conventional list experiment, the treatment group respondents see a greater number of items (N 1) than the control group respondents (N). This can lead to mechanical inflation in the mean response of the treatment group, simply because respondents see a greater number of items. We test this through a placebo control statement that is by design false for all respondents. Using original data, we find the N 1 item placebo group mean to be greater than N standard control group mean, even though there should be no difference in means between the groups. This clearly indicates the presence of mechanical inflation. Further, we show that this effect is most pronounced among elderly and low socioeconomic status respondents. We recommend using the essentially costless placebo statement in list experiment control groups as a preventive measure against potentially upward biased findings.

Keywords: List experiments, item count technique, survey design, placebo statement, respondent fatigue.

JEL Classification: C81, C83

Suggested Citation

Ostwald, Kai and Riambau, Guillem, Placebo Statements in List Experiments (May 9, 2017). Available at SSRN: https://ssrn.com/abstract=2965560 or http://dx.doi.org/10.2139/ssrn.2965560

Kai Ostwald

University of British Columbia (UBC) ( email )

1855 West Mall
Vancouver, British Columbia BC V6T 1Z4
Canada

HOME PAGE: http://www.kaiostwald.me

Guillem Riambau (Contact Author)

National University of Singapore (NUS) - Yale-NUS College ( email )

Singapore

Paper statistics

Downloads
16
Abstract Views
117
PlumX