Leah Boustan Publications

The diffusion of computerized machine tools in the mid-20th century was a pivotal step in the century-long process of factory automation. We build a novel measure of exposure to computer numerical control (CNC) using initial variation in tool types across industries and differential shifts toward CNC by type. Industries more exposed to CNC from 1970–2007 increased labor productivity and reduced production employment. Workers in more exposed labor markets adjusted by shifting from metal to non-metal manufacturing. Union members were shielded from this job loss, and some workers returned to school to retrain.

We provide the first nationally representative long-run series (1870–2020) of incarceration rates for immigrants and the US-born. As a group, immigrants have had lower incarceration rates than the US-born for 150 years. Moreover, relative to the US-born, immigrants’ incarceration rates have declined since 1960: immigrants today are 60 percent less likely to be incarcerated (30 percent relative to US-born Whites). This relative decline occurred among immigrants from all regions and cannot be explained by changes in observable characteristics or immigration policy. Instead, the decline is part of a broader divergence of outcomes between less-educated immigrants and their US-born counterparts.