We study a mechanism design problem where a community of agents wishes to fund public projects via voluntary monetary contributions by the community members. This serves as a model for public expenditure without an exogenously available budget, such as participatory budgeting or voluntary tax programs, as well as donor coordination when interpreting charities as public projects and donations as contributions. Our aim is to identify a mutually beneficial distribution of the individual contributions. In the preference aggregation problem that we study, agents report linear utility functions over projects together with the amount of their contributions, and the mechanism determines a socially optimal distribution of the money. We identify a specific mechanism -- the Nash product rule -- which picks the distribution that maximizes the product of the agents' utilities. This rule is Pareto efficient, and we prove that it satisfies attractive incentive properties: it spends each agent's contribution only on projects the agent finds acceptable, and agents are strongly incentivized to participate.
翻译:我们研究一个机制设计问题,即一个代理机构希望通过社区成员自愿的货币捐款为公共项目提供资金,这可以作为公共支出的模式,而没有外部可用的预算,例如参与性预算编制或自愿税收方案,以及捐助者在将慈善机构解释为公共项目和捐款时进行协调。我们的目的是确定个人捐款的互利分配。在我们研究的优惠汇总问题中,代理机构报告项目方面的线性公用事业职能及其捐款数额,该机制决定了资金的社会最佳分配。我们确定了一个具体机制 -- -- 纳什产品规则 -- -- 选择分配能够最大限度地增加代理机构公用事业产品的分配方式。这一规则是Pareto高效的,我们证明它符合有吸引力的激励特性:它只将每个代理机构的捐款用于代理机构认为可以接受的项目,而且代理机构被强烈鼓励参与。