Time discounting, ambiguity aversion, and preferences for future environmental policies : evidence from discrete choice experiments

Designing efficient environmental policies requires knowledge about households’ preference parameters for their intertemporal decisions. By conducting an original Internet-based survey using Japanese participants (n=2,906) and a follow-up survey (n=1,407), we examine how people evaluate pro-environmental policies depending on their individual attributes. The discount rates for environmental outcomes are estimated by using a discrete choice experiment. We show that participants’ discount rates in environmental policy choices are on average negative and future-biased. Those who are more ambiguity-averse and patient for money concerns, and anticipate more rapid increases in future temperatures are more willing to incur present-day tax burdens to ensure future environmental improvements. These results are highly robust against alternative estimation models and stable when using the follow-up survey data obtained 21 months later.