cost benefit analysis has gone through cycles of favour and disfavour in the uk. currently, it is in favour. This may not be obvious from casual inspection of government and regulatory agency activity, but it is clear that cost benefit analysis studies are multiplying and that they are exerting influence. there are more studies than might be thought, and they are having more bearing on individual pieces of legislation than might be thought. but their role should not be exaggerated. There is a much smaller tradition of using cost benefit analysis for regulatory appraisal and for damages settlements in europe than there is in the usa. in the uk, notable developments that are leading to a change in that situation are the development of formal regulatory appraisal for all new regulation, and the requirements upon the environment agency to use cost benefit analysis. in mainland europe, a similar stimulus has come from articlr 130R of the treaty on european union. If damage legislation were ever to develop in Europe, there would be further stimulus to benefit estimation. one area where benefit estimation could be expected to develop is in the public inquiry process. Surprisingly, few public inquiries are informed by benefit estimate, an issue that requires a seperate explanation on some other occasion