Combinatorial Voting

许多选举通过一次投票同时决定多个问题。某些问题的可取性取决于其他问题的解决方式：一个典型的加州投票包括支出计划、债券措施和税收提案，它们共同影响州和地方政府的财政状况。由于这种不可分离性，对多个问题的战略投票引入了单一问题选举所没有的微妙考虑。例如，只有在增加销售税的提议也获得批准以减轻为债券融资的财政负担的情况下，选民才可能支持学校债券措施。然后，在决定她对债券措施的投票时，她应该考虑补充增税被批准的可能性。此外，由于她对债券措施的投票只有在她是关键人物时才有意义，因此她应该在其他选民对债券措施平分的假设下，对增税的可能性加以限制。本项目开始了对具有相互依赖问题的选举的均衡分析。现有的战略投票模型要么考虑单一问题，要么假设偏好在不同问题之间是可分离的。对于本提案中考虑的更一般的环境，以下关于战略投票的基本问题尚未解决：是否存在投票均衡？这种均衡的特征是什么？随着选民人数的增加，它会如何表现？这种均衡的效率有多高？ 研究人员在一个不确定的投票环境中研究这些问题，该环境被建模为贝叶斯博弈。 该项目旨在比较不同机制在这些环境中的预期效率。例如，按顺序对一个问题进行投票，一次一个问题，逐步解决不确定性，并可能改善预期福利。第二，该项目旨在了解相互依存的价值观和多问题的信息汇总。特别是，如果每个选民都收到一个关于不同组合的公共值的噪声信号，那么随着选民（因此信息量）变大，最想要的捆绑几乎肯定会通过吗？更广泛的影响。美国有24个州和许多地方通过公民投票来决定一系列提案，从财产税到平权行动。公民投票在体制改进方面的任何进展都可能产生巨大的社会效益。 直接民主的普及使选民面临越来越多的问题，沿着，潜在的相互依存关系也成倍增加。本项目旨在了解不可分离性对投票的战略影响，以及它们对结果和福利的影响。

Many elections decide multiple issues simultaneously with a single ballot. The desirability of certain issues depends on how others are resolved: a typical California ballot includes spending initiatives, bond measures, and tax propositions which jointly impact the fiscal positions of state and local governments. With such nonseparabilities, strategic voting over multiple issues introduces subtle considerations absent from single-issue elections. For example, a voter might support a school bond measure only if a proposition to increase the sales tax is also approved to mitigate the fiscal burden of financing the bond. Then, in deciding her vote on the bond measure, she should consider the probability of the complementary tax increase being approved. Moreover, since her vote on the bond measure matters only if she is pivotal, she should condition the likelihood of the tax increase under the assumption that the other voters have split equally on the bond measure.This project commences the equilibrium analysis of elections with interdependent issues. Existing models of strategic voting either consider a single issue or assume that preferences are separable across issues. For the more general environments considered in this proposal, the following fundamental questions regarding strategic voting are yet unresolved: Does a voting equilibrium exist? How is this equilibrium characterized? How does it behave as the electorate becomes large? How efficient is this equilibrium? The researchers study these questions in a voting environment with uncertainty, modeled as a Bayesian game. The project seeks to compare the expected efficiency of different mechanisms for these environments. For example, voting sequentially over issues one at a time progressively resolves uncertainty and may improve expected welfare. Second, the project aims to understand interdependent values and information aggregation with multiple issues. In particular, if each voter receives a noisy signal regarding the common values of different combinations, will the most desired bundle pass almost surely as the electorate (hence the amount of information) becomes large?Broader impacts. Twenty-four American states and numerous localities use referenda to decide an array of propositions, ranging from property taxes to affirmative action. Any progress towards institutional improvements in referenda could yield large social benefits. The popularization of direct democracy presents voters with an ever-increasing number of issues, along with the accompanying multiplication in the number of potential interdependencies. This project seeks to understand the strategic effects of nonseparabilities on voting, and their consequent impact on outcomes and welfare.