INTRODUCTION

More than three decades have passed since 1954, when L. J. Savage published The Foundations of Statistics. The controversy raised by this book and Savage's subsequent writings is now part of the past. Many statisticians now use Savage's idea of personal probability in their practical and theoretical work, and most of the others have made their peace with the idea in one way or another. Thus the time may be ripe for a reexamination of Savage's argument for subjective expected utility.

Savage's argument begins with a set of postulates for preferences among acts. Savage believed that a rational person's preferences should satisfy these postulates, and he showed that these postulates imply that the preferences agree with a ranking by subjective expected utility. He concluded that it is normative to make choices that maximize subjective expected utility. To do otherwise is to violate a canon of rationality.

In the 1950s and 1960s, Savage's understanding of subjective expected utility played an important role in freeing subjective probability judgment from the strictures of an exaggerated frequent philosophy of probability. Today, however, it no longer plays this progressive role. The need for subjective judgment is now widely understood. Increasingly, the idea that subjective expected utility is uniquely normative plays only a regressive role; it obstructs the development and understanding of alternative tools for subjective judgment of probability and value.