DISCOUNTING ACROSS SPACE AND TIME IN CLIMATE CHANGE ASSESSMENT A Dissertation in Geography

Discounting is traditionally conceptualized as the comparison of the value of gains or losses that occur at different times. It endeavors to incorporate how humans trade off values to be received in the future versus value received immediately into economic analysis. Discounting has emerged as a key factor in assessments of climate change and other long-term environmental issues. However, the traditional time-only discounting neglects important spatial influences on how values are compared. This dissertation presents what is, to my knowledge, the most comprehensive effort to incorporate space into discounting as a theoretical, empirical, and applied concept. New discounting theory is presented that examines major reasons for discounting across time and finds that these reasons also hold for discounting across space. The theoretical work culminates in a new conceptualization of discounting that handles discounting across space as well as time while clarifying the philosophical basis for what is and is not discounting. New empirical research on discounting examines how humans discount across space and time and assesses the extent to which human values can be described in terms of discounting. This empirical research indicates that discounting by humans has strong spatial components and also that discounting is fundamentally limited as a paradigm for describing human values. Finally, new applied research illustrates how space-time discounting can advance our understanding of important societal issues through analysis of three cases of climate change adaptation. These cases – crop indemnity payments, the Commonwealth of Nations, and the nexus between climate change, migration, and conflict – show the importance of space-time discounting to cases of project evaluation, cooperation, and conflict. For example, the crop indemnity payments finds that when we do not account at all for space in project evaluations, or when we account for space with too coarse of a resolution, then our project evaluations can be significantly inaccurate. Taken together, this dissertation’s theoretical, empirical, and applied work show the importance of space to discounting as both an intellectual construct and a concept with very tangible practical significance. In short, the inclusion of space into discounting suggests major transformations to both the science and policy of discounting.