Measuring Issue Preferences: The Problem of Response Instability

The problem of response instability in survey measures of policy positions has been studied for over 20 years without any apparent resolution. Two major interpretations remain: Philip Converse's nonattitudes model and a measurement error model. One reason why neither interpretation has as yet been rejected or well supported is that previous analyses have depended on three-wave panel data that do not contain sufficient information to assess the goodness-of-fit of the models and also provide unreliable estimates of the error variance for the issue questions. Using five-wave panel data, this article first re-estimates the measurement models for the issue positions to assess goodness-of-fit and then estimates models of response instability to help establish its determinants. Evidence consistent with both interpretations of response instability is found. It thus appears as if neither model can adequately deal with the empirical characteristics of opinion questions in panel data. In the conclusion, a third interpretation of the response instability problem is offered that better accounts for the empirical findings and is more consistent with our understanding of public opinion.