The role of charging infrastructure and income on electric vehicle adoption

Abstract

This paper examines how the expansion of public charging infrastructure influences electric vehicle (EV) adoption across income levels. Using county-level panel data from Washington State (2019–2023), we estimate the marginal effect of new chargers on EV uptake and test for heterogeneity by income and charger type. We find that charger deployment increases EV adoption, but the effect is concentrated in high-income counties. Fast chargers generate larger and more widely distributed adoption gains than slower charging options, and income consistently conditions these effects. These patterns appear only in the battery electric vehicle (BEV) market; comparable models for plug-in hybrid vehicles (PHEVs) show no significant relationships. Robustness checks also indicate that charger deployment drives BEV growth rather than responding to it. These results highlight both the central role of infrastructure in enabling decarbonized transport and the risk that exclusive reliance on chargers may widen inequities, underscoring the need for complementary policies that expand access to zero-emission mobility. Charging investments alone may not yield equitable adoption outcomes and underscore the importance of complementary policies that address barriers to entry beyond charging availability.