# 1 Introduction

Ideally, elections for representative bodies result in the selection of those candidates that both perfectly represent the preferences of the electorate and design effective policies. In the real world, however, candidates with the qualities necessary to design effective policies are scarce. As a result, voters face a trade-off between voting for candidates with policy positions closest to their own and candidates who are intrinsically more capable of designing effective policies. How voters choose between these two kinds of candidates impacts the composition of representative bodies and, by extension, the representativeness and quality of public policy. While the trade-off between wellqualified candidates and candidates with agreeable policy positions is familiar to almost all who have voted, there is less appreciation of the role potentially served by electoral rules in mediating this trade-off and thereby producing differences in the composition of representative bodies and in the quality of public policy.

This paper seeks to identify the effects of differences in electoral systems —and district magnitude, in particular —on voter behavior, political selection, and policy outcomes. While numerous studies have posited links between electoral rules and policy outcomes (see Cox, 1997; Norris, 2004; Persson and Tabellini, 2000, 2005), explorations of the intermediate effects of voter incentives, political selection, and the qualities of elected representatives have been limited.<sup>1</sup> Moreover, diffi culties in identifying exogenous sources of variation in electoral systems have generally precluded causal inferences. This paper overcomes these two issues, making a theoretical and empirical contribution to the understanding of the effects of differences in electoral rules and policy outcomes. Specifically, the paper combines models of voter choice and legislative bargaining to generate predictions of how differences in district magnitude affect political selection and policy outcomes. These predictions are then tested using data from a unique experiment that induced randomized variation in rules for electing representatives to local development councils across 250 villages in Afghanistan.

The paper focuses on two alternate and commonly used electoral rules: the district election system and the at-large election system. District elections, which are used to elect the U.S. House of Representatives and the British House of Commons, are ‘single-winner systems’whereby successful candidates must attain at least a plurality of votes cast in their assigned electorate. District elections thus necessitate the division of the area to be represented into multiple geographic constituencies, with voters confined to casting votes for candidates competing to represent the voter’s constituency. At-large elections systems, which are a common means by which parliaments are elected in continental Europe, broaden the scope of the constituency over which candidates are elected. As a result, multiple candidates are elected by each constituency. In the extreme, an at-large election may contain a single constituency spanning the area represented by the particular body (e.g., an entire country in the case of a national parliament).

The theoretical model developed in the paper examines how these two different electoral rules affect the composition of a body of local representatives. The model considers a linear village with a uniform distribution of villagers. The location of a villager’s home corresponds to her ideal point

> 1 The importance of political selection, though emphasized as equally important as political accountability as early as the Federalist papers (Madison, 1788), has been largely “neglected” (see Besley, 2005, p. 44). Theoretical work by Myerson (1993) and recent empirical work on the quality of politicans by Hirano and Snyder (2014) provide a notable exception.

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