The Emergence of a Uniform Business Cycle in the United States: Evidence from New Claims-Based Unemployment Data
利用新数字化的失业保险索赔数据，构建了1947年以来的美国各州月度失业率序列，发现各州失业波动趋于一致，表明全国性商业周期自1960年代以来更加统一，并探讨了产业构成趋同的解释作用。
ABSTRACT: Using newly digitized unemployment insurance claims data, we construct historical monthly unemployment series for US states going back to January 1947. We validate our series, showing that they are highly correlated with the Bureau of Labor Statistics' state-level unemployment data, which are only available since January 1976, and capture consistent business cycle dynamics. We use our claims-based unemployment rates to study the postwar evolution of labor market adjustments to local demand shocks and state unemployment fluctuations around national recessions. We document: (1) a trend decrease in the dispersion of relative employment growth and unemployment across states; (2) an attenuation of relative employment, unemployment, and population responses to state-specific demand shocks in recent decades; and (3) a convergence across states in both the speed and degree to which unemployment recovers after recessions. These trends show the emergence of a national business cycle experienced more uniformly across US states, particularly since the 1960s. We present evidence suggesting that a convergence in states' industrial composition helps explain why a more uniform business cycle emerged when it did. And states' increasingly similar experience in recessions may help explain why interstate migration became a weaker adjustment mechanism in recent decades.