Abstract: Which climate investments should policymakers prioritize? We develop a framework that combines the Marginal Value of Public Funds (MVPF) with structural models of demand for green technologies to evaluate the welfare effects of environmental reforms. Our approach traces the MVPF across the entire policy spectrum using counterfactual simulations, thereby relaxing the constant-elasticity and “small-change” assumptions of sufficient-statistics methods. We apply our methodology to the Canadian electric vehicle market, following Fournel (2025). The analysis reveals strong nonlinearities in the cost-effectiveness of electric vehicle incentives: initial subsidies yield substantial welfare gains, but diminishing returns make large subsidies inefficient. At average subsidy levels, we estimate an MVPF of 1.07, indicating modest social returns. Counterfactual simulations suggest that investing in charging-station deployment generates the highest welfare gains, while taxing fuel-inefficient vehicles is not an efficient funding source.