International Trade and Macroeconomic Dynamics with Heterogeneous Firms*
构建了一个两国随机一般均衡模型，其中企业生产率不同，只有高生产率企业出口，模型能解释购买力平价的持久偏离和哈罗德-巴拉萨-萨缪尔森效应，并匹配美国及国际商业周期的若干特征。
We develop a stochastic, general equilibrium, two-country model of trade and macroeconomic dynamics.Productivity differs across individual, monopolistically competitive firms in each country.Firms face a sunk entry cost in the domestic market and both fixed and per-unit export costs.Only relatively more productive firms export.Exogenous shocks to aggregate productivity and entry or trade costs induce firms to enter and exit both their domestic and export markets, thus altering the composition of consumption baskets across countries over time.In a world of flexible prices, our model generates endogenously persistent deviations from PPP that would not exist absent our microeconomic structure with heterogeneous firms.It provides an endogenous, microfounded explanation for a Harrod-Balassa-Samuelson effect in response to aggregate productivity differentials and deregulation.Finally, the model successfully matches several moments of U. S. and international business cycles.