If Turnout Is So Low, Why Do So Many People Say They Vote?” Paper presented at

Aggregate survey estimates of voter participation rates generally exceed actual voter turnout rates, and sometimes by quite a lot. Figures 1 and 2 show that turnout estimates of both the National Election Studies Series and the Census Bureau Current Population Surveys always exceed the actual proportion of ballots cast by Americans who are eligible to vote in Presidential and midterm elections. For example, while 60 % of voting eligible population of the United States actually cast ballots in the 2004 Presidential election, 77 % of National Election Study respondents and 64 % of CPS citizen respondents said that they had voted. Several factors that contribute to the inflated reports of voter participation in surveys are well understood in the social science literature, including measurement error, panel attrition, panel conditioning, and non-random sampling errors (due to biases in contacting and responses). However, these have generally been addressed one at a time. This essay will highlight the disparate causes of inflated survey reports of participation, and use various NES data to provide an assessment of the magnitude of the various effects that result in survey overestimates. Figures 1 and 2 about here Measurement Error The most obvious factor contributing to survey overestimates of turnout is measurement error, or more specifically over-reporting (false positive responses) by people who actually faile