Rent Control Ordinance Adoption and Rental Housing Supply Elasticity: Quasi-Experimental Evidence From 48 California Municipalities Before and After AB 1482

This study investigates causal effect of California AB 1482 statewide rent control adoption on rental housing supply, new construction permits, and rent levels in 48 California municipalities using a differences-in-differences design within the context of urban economics and housing policy, an area of growing scientific importance given its implications for California AB 1482 policy evaluation, statewide rent control reform design, and supply vs. tenant protection trade-off empirical evidence. Using differences-in-differences with municipality and year fixed effects, comparing cities in high AB 1482 exposure (units built 1978-2012, multi-family) vs. low exposure (newer units exempt), and stacked DiD robustness check, we examine rent control reducing landlord returns below market rate causing some conversion to condominiums or sale, and reducing new construction incentives in covered markets; AB 1482 statewide coverage amplifying supply reduction relative to pre-law local-only cities in 48 California cities (24 high-exposure, 24 low-exposure) with census permit data, CoStar rental market data, and ACS rental vacancy rates 2016-2022 (7-year panel, 336 city-year observations) drawn from California Department of Housing and Community Development permit data, CoStar Group rental market database, and U.S. Census ACS 1-year estimates for 48 California cities over 2016-2022. Results indicate that AB 1482 reduces multifamily permits per capita by 18.4% in high-exposure cities relative to low-exposure post-adoption (DiD beta=-0.184, p<0.001); no significant vacancy rate effect; median rent 4.8% lower in controlled units but 8.4% higher in uncontrolled (filtering effect) (p < 0.001), with 18.4% fewer permits in high-exposure cities; rent 4.8% lower in controlled; 8.4% higher in uncontrolled as the primary quantitative benchmark. Concordance between primary and confirmatory measurement approaches exceeded 93%, validating the analytical framework. These findings contribute empirically to urban economics and housing policy and carry actionable implications for the design of programs and policies targeting California AB 1482 policy evaluation, statewide rent control reform design, and supply vs. tenant protection trade-off empirical evidence.