Corrupted Estimates? Response Bias in Citizen Surveys on Corruption

Measuring corruption has become a global industry. An important and commonly used data source are several large-scale multi-country projects that survey citizens directly about their perceptions and experiences of corruption. Such indicators are regularly used by political scientists to test theories on political attitudes and behavior. However, we still know little about the quality of many of these measures. This paper deploys a large survey with two embedded experiments to investigate two potential sources of bias in indicators based on citizens’ perceptions and experiences of corruption, stemming from political bias and sensitivity bias. First, I draw upon research on economic perceptions and argue that respondents are likely to respond in a political manner when asked how they perceive the level of corruption in their country. I test this argument by experimentally priming respondents’ political affiliations before asking for their perception of corruption. Second, I argue that standard questions probing peoples’ corruption experiences are likely to be subject to sensitivity bias. I test this second argument by constructing a list experiment. Overall, the results show strong and predictable sources of response bias that also vary significantly between important subgroups. I discuss implications for researchers and practitioners.