Logrolling and the power of single-mindedness

Journal of Economic Behavior and Organization. 2026. Vol. 248. Article 107642.

Samsonov A., Sole Olle A., Xefteris D.

We study a committee that decides on multiple issues and determines, for each, both the direction and the extent of reform, assuming that reform intensity is proportional to net support and that agents are ex ante symmetric. Within this environment, we investigate how logrolling shapes policy outcomes. We establish three main results. First, an essentially unique competitive equilibrium always exists. Second, logrolling improves the welfare of every committee member, and actually implements the Nash bargaining solution. Third, when the number of issues is sufficiently large, a single-minded delegate fully determines policy within her domain of interest. That is, the current analysis: (i) identifies a setting in which vote-trading may lead to stable outcomes, (ii) uncovers a link between a familiar political practice and a prominent welfare benchmark, and (iii) pins down one mechanism through which single-issue minorities may acquire disproportionate influence in representative democracies.

Keywords: политическая партия, общественное благосостояние, общее равновесие, голосование в политических органах, voting theory, Competitive equilibrium, Social welfare