The standard rationality hypothesis implies that behaviour can be represented as the maximization of a suitably restricted utility function. This hypothesis lies at the heart of a large body of recent work in economics, of course, but also in political science, ethics, and other major branches of social sciences. Though the utility maximization hypothesis is venerable, it remains an area of active research. Moreover, some fundamental conceptual problems remain unresolved, or at best have resolutions that are too recent to have (...) achieved widespread understanding among social scientists. The main purpose of the Handbook of Utility Theory is to make recent developments in the area more accessible. The editors selected a number of specific topics, and invited contributions from researchers whose work had come to their attention. Therefore, the list of topics and contributions is largely the editors' responsibility. Each contributor's chapter has been refereed, and revised according to the referees' remarks. This is the first volume of a two volume set, with the second volume focusing on extensions of utility theory. (shrink)

The purpose of this paper is to discuss the extent to which allowing for individuals to be indifferent among alternatives may alter the qualitative results that are obtained in social choice theory when domain restrictions are defined on profiles of linear orders. The general message is that indifferences require attention and careful treatment, because the translation of results from a world without indifferences to another where agents may be indifferent among some alternatives is not always a straightforward exercise. But the (...) warning is not one-directional: sometimes indifferences complicate the statement of results, but preserve their essential message. Sometimes, they help to create domains where some rules work better than in the presence of linear orders. In other cases, however, their presence destroys the positive results that would apply in their absence. I provide examples of these three situations. (shrink)