Endogenous Preference for Nonmarket Goods in Carbon Abatement Decisions

Long-term decisions, such as decisions about carbon abatement, are usually based on the implausible assumption of constant social preference. This paper focuses on a specific case of market and nonmarket goods, and it investigates the optimal climate policy when social preference for them is also changed by climate policy in a seminal climate-economy model: the Dynamic Integrated Model of Climate and the Economy (DICE) model with a single objective to maximize market goods consumption. We amend DICE to study an optimization problem that trades off the values of market and nonmarket goods, considering endogenous preferences. The relative price of non-market goods grows over time because of increases in both relative scarcity and the appreciation that represents the preference of it. As nonmarket goods are increasingly valuable relative to market ones, climate damages on nonmarket goods are increasingly expensive. The social cost of carbon, which aggregated climate impact on both goods, is consequently higher. Because abatement decision affects the valuation of nonmarket goods in the utility function, unlike previous climate-economy models, we solve the model iteratively by taking the obtained abatement rates from the last run as inputs in the current run. The results in baseline calibration advocate a more stringent climate policy, where endogenous social preference to climate policy raises the social cost of carbon further by roughly 12%-18% this century. Moreover, neglecting changing social preference leads to an underestimate of nonmarket goods damages by 15%. Climate policy is self-reinforced if it favors the more expensive consumption good. The proposed method can be applied to other long-term problems with endogenous preferences.