The researchers examine several aggregate measures of ticket splitting which have been proposed and/or employed in the literature. We then evaluate the accuracy of these aggregate measures by comparing the estimates of ticket-splitting with actual ticket-splitting in one community, ascertained from its 1972 and 1976 election ballots. Finally, we assess the hazards of drawing conclusions about ticket-splitting based on aggregate measures of the phenomenon.
Studies of split-ticket voting run the risk of inaccurate inferences when they rely on aggregate election data (Gitelson 1978). Burnham (1965) and Rusk (1970), for example, use the difference in partisan vote proportions for different office contests to make statements about individual ticket splitting. Yet Cowart claims (1974: 110-12) that this indicator is necessarily a conservative measure of the true level of ticket-splitting, always to the actual level. Others, for example DeVries and Tarrance (1972) and Phillips (1975), use split partisan outcomes for two elected offices to discuss levels of individual ticket-splitting. Both these indicators, difference in partisan proportions and split outcomes, may misestimate the number and proportion of split tickets as well as give rise to incorrect comparisons between communities or elections with regard to levels of ticket-splitting. They bear no necessary relationship to the actual number of split ballots. The data and discussion which follow raise questions about the degree of distortion arising from two aggregate measures of ticket splitting.