THE DECLINE OF OVER-TIME COMPARABILITY IN THE NATIONAL ELECTION STUDIES

The National Election Studies conducted by the University ofMichigan Survey Research Center and Center for Political Studiesprovide the best data set for studying the political attitudesand behavior of the American electorate. The American NationalElection Studies Data Sourcebook, which complies NES surveyresults between 1952 and 1978, demonstrates the extent to whichthese surveys facilitate over-time analysis. This article usesthe Sourcebook as a baseline and shows that there has been asubstantial decline in the over-time comparability of itemsmeasuring public policy preferences and of items measuring supportfor the political system.