["Business Strategy and the Environment, EarlyView. ", "\nABSTRACT\nThis study tests whether pro‐environmental purchasing behavior (PPB) cultivates environmental citizenship. We analyze survey data from 1816 residents across seven French metropolitan areas using partial least squares structural equation modelling combined with necessary condition analysis. Environmental knowledge and related antecedents predict PPB; in turn, PPB increases both political and social participation (PSP) and internal political efficacy (IPE). Crucially, a sufficiency‐necessity design reveals an asymmetric causal structure: PPB is a sufficient antecedent of both PSP and IPE, but a necessary condition only for PSP. Hence, the behavioral and cognitive facets of environmental citizenship follow distinct developmental pathways. The findings refine theory by clarifying when private consumption translates into public engagement—and when it does not. They also inform firms and policy‐makers seeking to expand green markets while mobilizing civic environmental engagement: initiatives that raise PPB are likely to unlock participation, whereas IPE may require complementary cognitive interventions beyond consumption.\n"]