Revise and Resubmit at the Journal of Political Economy
We explore what private market data can tell us about the appropriate discount rates for valuing investments in climate change abatement. We estimate the term structure of discount rates for real estate up to the very long horizons relevant for investments in climate change abatement. The housing term structure is downward sloping, reaching 2.6% at horizons beyond 100 years. We also show that real estate is exposed to both consumption risk and climate risk. We explore the implications of these new data using a tractable asset pricing model that incorporates important features of climate change. Climate change is modeled as a rare catastrophic event, the probability of which increases with economic growth. Economic activity partially mean reverts following a climate disaster, capturing the ability of the economy to adapt. As a result, short-run cash flows are more exposed to climate risk than long-run cash flows, allowing us to match the observed housing term structure. The model and data provide simple yet powerful guidance for appropriate discount rates for investments that hedge climate disaster risk. The term structure of these discount rates is upward-sloping but bounded above by the risk-free rate. For extremely far horizons at which we do not observe the risk-free rate, the estimated long-run discount rates for housing (a risky asset) provide an upper bound that becomes tighter with maturity. This suggests that the appropriate discount rates for investments in climate change abatement are low at all horizons, substantially below those conventionally used for valuing these investments and for determining the social cost of carbon.