Experiments in Producing Nonresponse Bias

While nonresponse rates in household surveys are increasingin most industrialized nations, the increasing rates do notalways produce nonresponse bias in survey estimates. The linkagebetween nonresponse rates and nonresponse bias arises from thepresence of a covariance between response propensity and thesurvey variables of interest. To understand the covariance term,researchers must think about the common influences on responsepropensity and the survey variable. Three variables appear tobe especially relevant in this regard: interest in the surveytopic, reactions to the survey sponsor, and the use of incentives.A set of randomized experiments tests whether those likely tobe interested in the stated survey topic participate at higherrates and whether nonresponse bias on estimates involving variablescentral to the survey topic is affected by this. The experimentsalso test whether incentives disproportionately increase theparticipation of those less interested in the topic. The experimentsshow mixed results in support of these key hypotheses.