12 - Nonignorable Nonresponse in Political Surveys

Summary

This chapter illustrates how to use randomized response treatments to assess possible nonresponse bias. It focuses on a 2019 survey and shows how nonignorable nonresponse may have deflated Trump support in the Midwest and among Democrats even as nonignorable nonresponse inflated Trump support among Republicans. We also show that Democrats who responded to the poll were much more liberal on race than Democrats who did not respond, a pattern that was particularly strong among White Democrats and absent among non-White Democrats. Section 12.1 describes a survey design with a randomized response instrument. Section 12.2 discusses nonignorable nonresponse bias for turnout questions. Section 12.3 looks at presidential support, revealing regional and partisan differences in nonignorable nonresponse. Section 12.4 looks at race, focusing on partisan and racial differences in nonignorable nonresponse. Section 12.5 assesses nonignorable nonresponse on climate, taxes, and tariffs.