WHAT CAN WE LEARN WITH STATISTICAL TRUTH SERUM? DESIGN AND ANALYSIS OF THE LIST EXPERIMENT

Due to the inherent sensitivity of many survey questions, a number of researchers have adopted an indirect questioning technique known as the list experiment (or the item-count technique) in order to reduce dishonest or evasive responses. However, standard practice with the list experiment requires a large sample size, utilizes only a difference-in-means estimator, and does not provide a measure of the sensitive item for each respondent. This paper addresses all of these issues. First, the paper presents design principles for the standard list experiment (and the double list experiment) for the reduction of bias and variance as well as providing sample-size formulas for the planning of studies. Second, this paper proves that a respondent-level probabilistic measure for the sensitive item can be derived. This provides a basis for diagnostics, improved estimation, and regression analysis. The techniques in this paper are illustrated with a list experiment from the 2008-2009 American National Election Studies (ANES) Panel Study and an adaptation of this experiment.