Is the Mandated EV-Ready Policy by the Local Government Truly Electric Vehicle (EV) Ready?

EV-integrated building codes serve as one of the innovative tools that local government, such as cities and county administrations, can implement to promote electric vehicle (EV) adoption. Despite the importance of this policy, there is less evidence demonstrating its impact. In this study, we analyzed EV registration data from Maryland spanning 1999 to 2024 to evaluate the effectiveness of EV-ready policies in the building sector implemented by local governments on EV adoption. Using a synthetic difference-in-differences design, we found that EV-ready policies resulted in a 0.25 increase in EVs per census block, corresponding to an 8% rise in EV adoption directly attributable to the policy. Moreover, our analysis of the distributional effects of this policy reveals that the benefits are predominantly realized by communities with higher incomes and greater concentrations of single-family dwellings. These findings carry significant policy implications for local governments seeking to foster more equitable EV adoption and contribute to the broader discussion on how to motivate local governments to take more ambitious actions in addressing global climate challenges.