AI 中文总结
该论文针对存在最小有效规模代理人技术、斯彭斯-米尔利斯条件失效的筛选问题，研究了单调划分曲线与松弛解的相交方式，得出最优契约的三分法规则，并通过对偶方法证明了最优解的全局最优性。
AI 中文摘要
委托人对代理人进行筛选，代理人的技术存在最小有效规模，因此斯彭斯-米尔利斯条件沿一条单调划分曲线失效，该曲线上每一类型对边际产出的评价相等。对于此类划分曲线与松弛解均严格单调的情形，最优契约遵循三分法，由两者的相交方式决定：当两者永不相交时，跳跃不可能发生；当两者跨一条平坦划分曲线时，跳跃不可避免；当两者跨一条严格递增划分曲线时，跳跃是可选的。最优解并非推测得出，而是通过对偶化绑定约束族（借助显式权重）在所有可实施的分配（确定性或随机性）中被证明为全局最优；该证明既不要求线性原语，也不对契约形状施加任何限制。在适度正则条件下，此类情形恰好包含40种构型，每种构型均被映射至其强制形状、以闭式形式求解并得到证明。
英文摘要
A principal screens an agent whose technology has a minimum efficient scale, so the Spence-Mirrlees condition fails along a monotone dividing curve: the locus at which every type values marginal output equally. For the class in which this curve and the relaxed solution are both strictly monotone, the optimal contract obeys a trichotomy, governed by how the two meet: a jump is impossible when they never meet, unavoidable across a flat dividing curve, a choice across a strictly increasing one. The optimum is found, not conjectured: each solution is certified as globally optimal among all implementable allocations, deterministic or random, by dualizing the family of binding constraints through an explicit weight; the certificates require neither linear primitives nor any restriction on the shape of the contract. Under mild regularity the class comprises exactly forty configurations; each is mapped to its forced shape, solved in closed form, and certified.
Comments85 pages, 10 figures. Replication code: https://doi.org/10.5281/zenodo.21854607
