Labor Market Heterogeneity and the Aggregate Matching Function
估计总量匹配函数发现，匹配效率的残差呈顺周期波动并在2007年后大幅下降；考虑工人异质性和市场分割后，匹配效率变动源于失业者平均特征恶化或劳动力市场条件差异扩大。
We estimate an aggregate matching function and find that the regression residual, which captures movements in matching efficiency, displays procyclical fluctuations and a dramatic decline after 2007. Using a matching function framework that explicitly takes into account worker heterogeneity as well as market segmentation, we show that matching efficiency movements can be the result of variations in the degree of heterogeneity in the labor market. Matching efficiency declines substantially when, as in the Great Recession, the average characteristics of the unemployed deteriorate substantially, or when dispersion in labor market conditions—the extent to which some labor markets fare worse than others—increases markedly.