Book excerpt: Public choice theory should be taken seriously--but not too seriously. In this thought-provoking book, Jerry Mashaw stakes out a middle ground between those who champion public choice theory (the application of the conventional methodology of economics to political science matters, also known as rational choice theory) and those who disparage it. He argues that in many cases public choice theory's reach has exceeded its grasp. In others, public choice insights have not been pursued far enough by those who are concerned with the operation and improvement of legal institutions. While Mashaw addresses perennial questions of constitutional law, legislative interpretation, administrative law, and the design of public institutions, he arrives at innovative conclusions. Countering the positions of key public choice theorists, Mashaw finds public choice approaches virtually useless as an aid to the interpretation of statutes, and he finds public choice arguments against delegating political decisions to administrators incoherent. But, using the tools of public choice analysts, he reverses the lawyers' conventional wisdom by arguing that substantive rationality review is not only legitimate but a lesser invasion of legislative prerogatives than much judicial interpretation of statutes. And, criticizing three decades of "law reform," Mashaw contends that pre-enforcement judicial review of agency rules has seriously undermined both governmental capacity and the rule of law.