Inventories and the Business Cycle: An Equilibrium Analysis of ( S, s ) Policies
构建了一个均衡商业周期模型，其中非凸运输成本导致企业采用(S, s)库存政策。校准至美国战后数据后，模型再现了库存投资周期波动的三分之二，并挑战了库存放大总波动的传统观点。
We develop an equilibrium business cycle model where nonconvex delivery costs lead firms to follow (S, s) inventory policies. Calibrated to postwar US data, the model reproduces two-thirds of the cyclical variability of inventory investment. Moreover, it delivers strongly procyclical inventory investment, greater volatility in production than sales, and a countercyclical inventory-to-sales ratio. Our model challenges several prominent claims involving inventories, including the widely held belief that they amplify aggregate fluctuations. Despite the comovement between inventory investment and final sales, GDP volatility is essentially unaltered by inventory accumulation, because procyclical inventory investment diverts resources from final production, thereby dampening fluctuations in sales..