Multiparty Split-Ticket Voting Estimation as an Ecological Inference Problem

Abstract

The estimation of vote splitting in mixed-member electoral systems is a common problem in electoral studies, where the goal of researchers is to estimate individual voter transitions between parties on two different ballots cast simultaneously. Because the ballots are cast separately and secretly, however, voter choice on the two ballots must be recreated from separately tabulated aggregate data. The problem is therefore of one of making ecological inferences. Because of the multiparty contexts normally found where mixed-member electoral rules are used, furthermore, the problem involves large-table (R × C ) ecological inference. In this chapter we show how vote-splitting problems in multiparty systems can be formulated as ecological inference problems and adapted for use with King's (1997) ecological inference procedure. We demonstrate this process by estimating vote splitting in the 1996 Italian legislative elections between voters casting party-based list ballots in proportional representation districts and candidate-based plurality ballots in single-member districts. Our example illustrates the pitfalls and payoffs of estimating vote splitting in multiparty contexts, and points to directions for future research in multiparty voting contexts using R × C ecological inference.

An evaluation of the performance and suitability of R × C methods for ecological inference with known true values

“… 2 Voting solely for either a party or a candidate is possible. As discussed by Benoit et al ( 2004 ) the observed totals of valid votes for different ballots always differ slightly, mainly because of different rates of invalid ballots. As for Benoit et al ( 2004 ) we took the total number of votes to be the midpoint between the two ballot totals in the rare occasions when this was a problem.…”

Expressive and Strategic Behavior in Legislative Elections in Argentina

“…This combination makes the statistical portion of the model less sensitive to assumptions than previous statistical methods (see Goodman 1959) that exclude information from the bounds (King et al 2004). Ecological inference methods have been used to disentangle the composition of the Nazi vote (King et al 2008), ticket-split voting (Burden and Kimball 1998;Benoit et al 2004;Giannetti and Laver 2000), electoral turnout by race (King 1997;Gay 2001), residual vote rates (Herron and Sekhon 2005), the relationship between centerright vote and turnout (Calvo and Escolar 2003), among others. Other methods have been proposed to estimate voter transitions between two consecutive elections.…”

R×CEcological Inference: Bounds, Correlations, Flexibility and Transparency of Assumptions

“…the 'single regression' of Grofman et al (1985)) or rows (e.g. Benoit et al (2004)) proceeds via an undesirable assumption that cells corresponding to a particular category exhibit no systematic patterns. Collapsing methods (e.g.…”