PACER: Political Acceptability for Coalition-Enabling Representative Mandates

This paper explores how richer electoral information can improve government formation while preserving proportional representation. We introduce Political Acceptability for Coalition-Enabling Representative Mandates (PACER), an electoral framework that allows voters to express support for multiple politically acceptable parties rather than selecting only a single preferred party.

Existing proportional electoral systems reveal voters' preferred parties but provide limited information about which governing arrangements voters would regard as acceptable. As party systems become increasingly fragmented, this missing information may contribute to prolonged coalition negotiations and difficulties in forming stable governments.
        
PACER incorporates voter-expressed political acceptability into the electoral process, enabling the identification of multiple democratically legitimate governing arrangements. Among these, the Rule of Minimal Deviation selects the arrangement requiring the smallest deviation from the proportional election outcome.
        
The paper develops the mathematical framework underlying PACER, discusses alternative design variants, and illustrates the proposed mechanism through hypothetical vote-splitting examples and an exploratory empirical analysis based on Swedish voter-flow data. The framework is exploratory and intended to stimulate further theoretical and empirical research into vote-splitting electoral systems, political acceptability, and democratic institutional design.