@techreport{NBERw13490, title = "Structural Uncertainty and the Value of Statistical Life in the Economics of Catastrophic Climate Change", author = "Martin Weitzman", institution = "National Bureau of Economic Research", type = "Working Paper", series = "Working Paper Series", number = "13490", year = "2007", month = "October", URL = "http://www.nber.org/papers/w13490", abstract = {Using climate change as a prototype motivating example, this paper analyzes the implications of structural uncertainty for the economics of low-probability high-impact catastrophes. The paper shows that having an uncertain multiplicative parameter, which scales or amplifies exogenous shocks and is updated by Bayesian learning, induces a critical "tail fattening" of posterior-predictive distributions. These fattened tails can have strong implications for situations (like climate change) where a catastrophe is theoretically possible because prior knowledge cannot place sufficiently narrow bounds on overall damages. The essence of the problem is the difficulty of learning extreme-impact tail behavior from finite data alone. At least potentially, the influence on cost-benefit analysis of fat-tailed uncertainty about the scale of damages -- coupled with a high value of statistical life -- can outweigh the influence of discounting or anything else.}, }