The Persistence of Local Joblessness
研究了美国通勤区就业人口比率的长期差异，发现这些差异反映了真实的经济机会差距，且因劳动力需求冲击的高持续性而难以消除，人口迁移总是滞后于就业变化。
Differences in employment-population ratios across US commuting zones have persisted for many decades. We claim these disparities represent real gaps in economic opportunity for individuals of fixed characteristics. These gaps persist despite a strong migratory response, and we attribute this to high persistence in labor demand shocks. These trends generate a “race” between local employment and population: population always lags behind employment, yielding persistent deviations in employment rates. Methodologically, we argue the employment rate can serve as a sufficient statistic for local well-being; and we model population and employment dynamics using an error correction mechanism, which explicitly allows for disequilibrium.