It’s long been clear that urbanization and automated technologies are shaping society, but it hasn’t been obvious how the two forces affect each other.

Until now, perhaps. A new study from MIT’s Media Lab posits that the smaller the city, the greater the impact it faces from automation. The finding, they say, could encourage legislators to pay special attention to workers in smaller cities and offer them support services.

Other researchers have attempted to measure the effect of technology on employment in cities, but the Media Lab authors, who have identified which jobs and skills tend to be more prevalent in smaller cities and larger ones, claim to be the first to explain why different U.S. cities are more susceptible (or resilient) to technological unemployment. (Though the authors did not define “small” and “large” in their paper, they say that cities with fewer than 100,000 inhabitants will experience more disruption.)

They say that bigger cities have a disproportionately large number of jobs for people who do cognitive and analytical tasks, such as software developers and financial analysts—occupations that are less likely to be disrupted by automation. Smaller cities have a disproportionate amount of routine clerical work, such as cashier and food service jobs, which are more susceptible.