A central challenge in mechanism design is to develop truthful trade mechanisms that maximize the expected gains-from-trade (GFT) in two-sided markets with strategic agents. As achieving the full GFT is generally impossible, much of the literature has focused on constant-factor approximations. Existing results, however, are limited to the highly structured settings of bilateral trade and double auctions, in which every buyer can trade with every seller. We consider the significantly more general setting of two-sided matching markets with arbitrary downward-closed constraints on the family of allowed matchings. For this setting, we present a simple randomized truthful mechanism that guarantees a constant-factor approximation to the optimal expected GFT. This result also resolves an open problem posed by Cai, Goldner, Ma, and Zhao (2021).

翻译：机制设计中的一个核心挑战是开发诚实的交易机制，以最大化具有策略性代理的双边市场中的预期贸易收益（GFT）。由于实现完全GFT通常是不可能的，大量文献聚焦于常数因子近似。然而，现有结果仅限于高度结构化的双边交易和双向拍卖环境，其中每个买家可与每个卖家交易。我们考虑更具一般性的双边匹配市场环境，其中允许的匹配族受任意向下封闭约束。对于这一环境，我们提出一个简单的随机诚实机制，保证对最优预期GFT实现常数因子近似。该结果同时解决了蔡、戈尔德纳、马和赵（2021）提出的一个开放问题。