Mayors strike back: Evidence from land use regulation

When a national government relaxes a local regulation, do local ocials comply, or find other ways to keep the same rules in place? We study a 2014 French reform that abolished floor area ratios (FAR), a widely used cap on building density, with the explicit goal of expanding housing construction. We assemble a new geospatial panel tracking three zoning tools floor area ratios, building heights, and coverage ratios | over 15 years across 118 municipalities in the Paris region, linked to building permits, housing stock, and transaction prices. Comparing municipalities where FAR existed before the reform to those where it did not, we show that local governments o set the deregulation by tightening the two instruments they retained: maximum heights fell, coverage ratios tightened, and permit denials rose. Density did not increase in previously regulated areas, and we detect no e ect on prices, consistent with the limited change in supply. The regulatory tightening was strongest where mayors faced closer elections and where property values are higher, not where mayors belong to parties opposing the reforming government, pointing to electoral accountability rather than partisanship. Top-down deregulation can therefore be substantially undercut when local governments retain complementary instruments, suggesting reforms must either limit local discretion directly or realign local incentives.