Urban Elevators and the Geography of Labor Market Polarization

Large cities gain abstract jobs and shed routine jobs faster than small ones. Whether this divergence arises because workers move across locations or because workers' labor market careers differ across locations matters for welfare and policy, and cross-sectional data cannot tell the two apart. Using the French administrative panel DADS–EDP (1984–2021), we decompose the change in each occupation's employment share, by city size, into within-city occupational switches, cross-city relocation, combined moves, and non-employment flows. The divergence is produced inside cities. We find that large cities move workers from routine to abstract jobs at twice the rate of small cities, and this flow more than accounts for the urban gap in abstract employment. The routine decline is absorbed by upgrading into abstract work, not by downgrading into manual services. This urban elevator predates the 1994 onset of French polarization and operates within occupations - holding worker characteristics and the occupation of origin fixed, staying in a large city raises the rate of upgrading by about 40%, for college and non-college workers alike. The evidence places the burden of explanation on agglomeration forces that act on occupational mobility within cities rather than on the sorting of heterogeneous workers across them.