Over the last week we have heard a lot about the prediction of the N.C. Coastal Resources Commission’s Science Panel on Coastal Hazards, an effort supported by the NC Department of Environment and Natural Resources. The panel’s prediction? Sea level will rise 1 meter, or 39 inches, along the NC coast by the year 2100. As an economist I cannot offer and expert opinion about the commission’s science, but I hope it is more rigorous than its statistics. The panel’s prediction lacks necessary statistical rigor and is therefore not very useful for serious policy analysis. It makes a prediction but assigns no probability to it other than to say that is is “likely,” while giving no rigorous, i.e., quantitative, definition of what “likely” means. This makes the prediction useless for conducting rigorous economic cost-benefit analysis, which should be the basis for public policy. If you can’t use the prediction in a rigorous sense for determining whether the benefits to society of a particular policy proposal or regulation outweigh the costs then it is not a very good prediction for the purposes that I presume DENR had in mind when commissioning the report, i.e. formulating policy.
We have been hearing a lot this week about the science of all this and who has credentials and who doesn’t, but the fact is that at the end of the day the bottom line question is one of economics not science. Of course the economic analysis must be informed by scientific analysis. Unfortunately the scientific commission did not provide enough information to conduct an informed, rigorous economic assessment. This would require a prediction that is associated with a quantifiable probability statistic.