Introduction

Rarely does a result so spectacular and fundamental come along that it forces us to revamp how we view a subject. This happened in 1951 when Kenneth Arrow published his Ph.D. thesis as the book Social Choice and Individual Values.

The effect of Arrow's stunning, seminal contribution was to create serious doubt about commonly accepted beliefs concerning decision procedures. This sense of doubt is so pervasive that it affects even the economic and political decision approaches so commonly used in our democratic societies.

Arrow accomplished all of this by listing properties sufficiently basic and natural that it is reasonable to expect them to be satisfied by all decision and election methods — particularly those employed by a democracy. Arrow's punch line was that requiring decision procedures to fill these conditions exacts a heavy cost. Once there are three or more alternatives, these requirements can be satisfied only by a dictator.

A dictator! What a predicament. By contradicting expectations and common sense, by showing that basic properties mandate a dictator, his conclusion raises serious doubts about fundamental democratic principles. As it is to be expected, Arrow's “dictatorial” assertion has been associated with all sorts of dire Draconian consequences.

More responsible commentary emphasized how Arrow's seminal result speaks to the basics of choosing. In a fundamental sense it addresses the quandary raised in the last chapter about selecting a decision procedure. This is because Arrow's result ensures that all non-dictatorial decision procedures are plagued with basic flaws.