How do short‐term rental regulations affect market outcomes? Evidence from San Francisco's Airbnb registration requirement

We study the effects of San Francisco's Airbnb registration requirement on market outcomes. The policy reduced Airbnb availability by 20%–27%, nights booked by 22%–31%, and increased booking prices by 3.3% relative to listings in untreated surrounding cities. Relatively commercial listings experience larger availability and booking decreases than casual listings, and similar increases in booking prices. The fraction of available listings designated as commercial fell by 2 p.p. (15%) in the most Airbnb‐dense neighborhoods. Overall, the policy reduced nights booked by 27,182/month and hosts' revenue by $5 million/month. Long‐term housing prices also fell following enactment, suggesting an improvement in housing affordability.