The reader will note that I do not reach any final conclusion or provide a neat summary in this book. This choice is deliberate and is based on my belief that the subject cannot be summed up in any useful way. On the one hand, I find myself at this point somewhat overwhelmed by the sheer volume of material in the theory of public economics. Indeed, I am a little embarrassed when I realize how many subjects have been ignored or at best treated in a cursory manner in this book. On the other hand, I am somewhat discouraged at the prospect of doing the sort of good applied project analysis that I have tried to espouse. The kind of information necessary to evaluate demands for collective goods, correctly incorporate equity considerations, measure unemployment benefits, or compute risk discount factors is very difficult to come by even in the world of small projects much less the general framework of Part IV. To the extent that I set out to provide practical methods, I have promised more than I can deliver.

Although it seems unreasonable to expect operational cookbook recipes for project analysis anytime soon, there are important practical lessons to be learned from the modern theory surveyed here. In particular, this theory can help us identify faulty methods and decisions; partly for this reason, I spent a lot of time explaining what not to do and identifying biases that will result from incorrect procedures.