Mechanism design with general ex-ante investments
研究了代理人隐藏行动影响状态分布时的机制设计问题，发现当行动空间足够大时，诱导目标行动组合的支付规则唯一，并证明纯VCG机制是唯一能产生有效行动组合的机制，而枢轴机制则常失效。
We investigate mechanism design problems wherein agents take hidden actions that affect the state distribution. As agents’ action space expands, the set of mechanisms that yields a targeted action profile reduces. When agents can choose from various actions to change the state distribution in full-dimensional directions, the payment rule that induces a targeted action profile along with a given allocation rule becomes unique up to a constant. We subsequently utilize this characterization result to examine efficient mechanism design and demonstrate that the pure-VCG mechanism, the most basic form of the canonical VCG mechanism, is the only mechanism that produces an efficient action profile when agents can choose from various actions. Contrarily, the widely used pivot mechanism frequently fails to induce an efficient action profile as long as an agent’s action impacts the private types of other agents, even if the agent’s action space is one-dimensional.