Passage 4 Costing Catastrophe
人类准备好应对灾难了吗？ 《经济学人》

[00:00]Would people be prepared to pay to avoid future disasters? And if so,
[00:07]how much? That is the question tackled by Robert Pindyck
[00:13]of MIT's Sloan School of Management in a recent paper.
[00:19]It is not easy to calculate accurately the likelihood of disasters.
[00:25]Some, such as rising sea levels or nuclear weapons gone rogue,
[00:31]have few historical precedents on which to base estimates.
[00:37]So Messrs Pindyck chose instead to model how likely people think it is that
[00:44]a catastrophe will occur,
[00:47]and how much money they would be prepared to spend to prevent it.
[00:53]In his model, the hypothetical household had to decide both the likelihood
[01:00]of a potential catastrophe and its magnitude,
[01:04]since a high-risk disaster with little consequence
[01:08]would affect spending behavior differently to a rare but devastating event.
[01:16]The model has the disadvantage of being,
[01:19]like many economic models, theoretical.
[01:24]But it has the advantages of not requiring people
[01:29]to have perfect information about the future,
[01:34]and being applicable to any disaster-not just climate change,
[01:39]but flu epidemics or widespread warfare.
[01:44]Sky-is-falling economic modeling, so to speak, is not new.
[01:50]Two decades ago a paper by Thomas Reitz, then of the University of Iowa,
[01:59]pointed out that equity owners, even while acting averse to risk,
[02:05]demand high rates of return in anticipation of an unlikely, but severe, crash.
[02:14]More recently Richard Posner, of the University of Chicago,
[02:20]has argued at length that governments should spend more to prevent disasters
[02:26]that will probably not happen, but would be awful if they did.
[02:31]Mr Posner's blogging partner, Gary Becker, an economist,
[02:37]estimated in May the worldwide willingness to pay to avoid another flu pandemic
[02:45]at about $200 billion, even assuming the probability of such a pandemic occurring
[02:54]at only 1% over the next 20 years.
[02:59]Messrs Pindyck's study lends credence to previous work
[03:04]which maps not only the probability of a risk occurring,
[03:09]but also the expected damage should it occur. In his model,
[03:16]even when a hypothetical consumer estimates the risk of a disaster occurring is close to zero,
[03:25]he still estimates the scale of potential devastation to be
[03:30]between 26% and 32% of national capital stock, far greater
[03:37]than the effects of Hurricane Katrina or even the 2004 tsunami.
[03:44]To avoid such a disaster entirely, or reduce its impact,
[03:49]the households in the model would be willing to pay a permanent consumption tax of up to 15%,
[03:57]depending on the size of the reduction and the likelihood of catastrophe.