We present a restriction on the domain of individual preferences that is both necessary and sufficient for the … preferences be contractible. Contractibility admits a straightforward intuitive explanation, and is a generalisation of conditions …

preferences: the space of strictly quasiconcave preferences Psco, its subspace of smooth preferences Pssco, and a space P1 of … smooth (not necessarily convex) preferences with a unique interior critical point (a maximum). The results are proven using …

core of an economy [13, 14, 15, 16, 17]. The space of monotone preferences is contractible; as shown already in [6, 17 …] such that spaces admit social choice rules. However, monotone preferences are of little interest in social choice theory …

We study the aggregation of preferences when intensities are taken into account: the aggregation of cardinal … preferences, and also of von Neumann-Morgenstern utilities for choices under uncertainty. We show that with a finite number of … choices there exist no continuous anonymous aggregation rules that respect unanimity, for such preferences or utilities. With …

preferences, which define the individual optimization problems, is topologically nontrivial, and that its topological complexity … is responsible for the impossibility of treating several individual preferences as if they were one, i.e., aggregating …

opinions. Voting is an obvious way in which societies aggregate individual preferences to obtain social ones. The procedure of … voting registers individual comparisons between alternatives, called ordinal preferences, rather than intensities of … preferences among these alternatives, called cardinal preferences, and this is one source of so-called paradox of social choice …

The problem of endowing preferences with manifold structures emerged from discussions with Gerard Debreu in 1975 . Time …) spaces of smooth preferences were endowed with a Hilbert manifold structure, and this was used to study the existence and … structural stability of competitive equilibria in economies where preferences might be non-monotonic and non-convex . This paper …

possible to "use" the asset at a subsequent date. If there is uncertainty about future preferences or valuations, then …