Commodity Market Dynamics and the Joint Executive Committee, 1880–1886
利用芝加哥和纽约的周度谷物现货与期货价格，构建预期运输成本、库存及预期误差，并将其纳入Porter的铁路卡特尔结构模型，半参数估计定价与需求方程，发现卡特尔稳定期的加价符合最优合谋定价，而不稳定期由预期错误触发。
Abstract Using weekly spot and future commodity prices in Chicago and New York, we construct expected transportation rates for grain between these two cities, expected inventory levels in New York, and realized errors in the expectations of such variables. We incorporate these exogenous commodity market dynamics into Porter's (1983) structural modeling of the Joint Executive Committee Railroad Cartel. As in Porter, we model marginal cost as a parametric function of (instrumented) output, among other factors. Unlike Porter, we model pricing over marginal cost as a nonparametric function of a set of variables, which include expectations of deterministic demand cycles and cartel stability. We estimate the pricing and demand equation simultaneously and semiparametrically. Our estimated weekly markups during periods of cartel stability are shown to reflect optimal collusive pricing over deterministic business cycles, as modeled in Haltiwanger and Harrington (1991). Periods of cartel instability are proven to be triggered by realized mistakes in expectations of New York grain prices.