ACCOUNTING FOR THE CYCLICAL DYNAMICS OF INCOME SHARES
研究了收入份额（劳动份额和利润份额）在商业周期中的动态特征，构建了一个包含企业进入成本和摩擦性劳动力市场的模型，成功复制了这些事实，并揭示了其与冲击放大和传导机制的联系。
Over the business cycle, labor's share of output is negatively but weakly correlated with output, and it lags output by about four quarters. Profits' share is strongly pro‐cyclical. It neither leads nor lags output, and its volatility is about five times that of output. Those assumptions relate to the structure of aggregate technology and the degree of competition in factor markets. Despite much evidence in favor of time‐varying income shares, macroeconomics still lacks models that can account for their time series facts. This article constructs a model that can replicate those facts. We introduce costly entry of firms in a model with frictional labor markets and find a link between the ability of the model to replicate income shares' dynamics and the ability of the model to amplify and propagate shocks. That link is a weak correlation between the real interest rate and output, a fact in U.S. data but a feature that models of aggregate fluctuations have had difficulty achieving.