在含平台费、税费与补贴的在线市场中寻找竞争均衡
Finding Competitive Equilibria in Online Marketplaces with Platform Fees, Taxes, and Subsidies
Taihei Oki, Ryosuke Sato
AI 速览：研究在带平台费、税费、补贴等分段线性转移的多单位交易网络中，如何用升价算法计算最小均衡价格向量与均衡配置。
We study equilibrium computation in multi-unit trading networks with valuations satisfying generalized full substitutes and agent- and transaction-specific piecewise-linear transfer functions. These transfers model platform fees, taxes, subsidies, and membership discounts in online marketplaces. Our ascending procedure raises prices at different rates and reaches the minimum equilibrium price vector in finitely many iterations, each implementable in strongly polynomial time under our oracle and arithmetic models. An equilibrium allocation can then be recovered efficiently. The method extends primal-dual techniques developed for ascending auctions to handle complementarities between purchases and sales through a submodular flow formulation. In single-seller markets with substitutes and complements, our framework also extends the double-track auctions of Sun and Yang (2009) and Shioura and Yang (2015) to bidder- and good-specific transfers.