Ryan Lewis, University of Colorado Boulder: The Value of Climate Hedge Assets: Evidence from Australian Water Markets
Abstract
In Australia’s Murray Darling Basin (MDB), short term (allocation) and long term (entitlement) water rights are separately traded, centrally reported, and disseminated to the public. I utilize this setting to demonstrate three primary findings concerning water rights and climate change risk. First, water rights appear to be a climate change hedge: in periods of diminishing supply, allocation cash flows spike as price increases offset quantity declines. Second, since 2014, entitlement prices in climate-exposed areas have increased approximately $1500 per MegaLitre (about 39%) more than prices in non-climate-exposed areas, while allocation prices have remained similar in both areas. These price differences provide a clear market signal about future scarcity and help define investment opportunities available today to preserve water resources. Finally, estimating the allocation cash-flow to rainfall elasticity and extrapolating using the 2050 IPCC rainfall scenarios, I attribute about 21% of the price effect to differences in expected cash flow, and the remainder to a lower discount rate. The premium I estimate equates to a 1.2% lower rate of return for climate hedge or mitigation assets, a critical parameter in climate economics.