We put forward a model of private goods with externalities. Agents derive benefit from communicating with each other. In order to communicate they need to have a language in common. Learning languages is costly. In this setting no individually rational and feasible Groves mechanism exists. We...

The class of preferences over opportunity sets ("menus") rationalizable by underlying preferences over the alternatives is characterized for the general case in which the dataset is unrestricted. In particular, both the universal set of alternatives and the domain of menus over which preferences...

Using the techniques of revealed preference analysis, we study a two-stage model of choice behavior. In the first stage, the decision maker maximizes a menu-dependent binary relation encoding preferences that are imperfectly perceived. In the second, a menu-independent binary relation is...

We investigate the computational complexity of several decision problems in hedonic coalition formation games and demonstrate that attaining stability in such games remains NP-hard even when they are additive. Precisely, we prove that when either core stability or strict core stability is under...

This paper extends the analysis of liberal principles in social choice recently proposed by Mariotti and Veneziani (2009a) to infinitely-lived societies. First, a novel characterisation of the inegalitarian leximax social welfare relation is provided based on the Individual Benefit Principle,...

We study a model of endogenous means testing where households differ in their income and where the in-kind transfer received by each household declines with income. Majority voting determines the two dimensions of public policy: the size of the welfare program and the means-testing rate. We...

A Hard Problem is a collective choice problem in which the only feasible alternatives apart from the status quo consist of a welfare gain to some people (the Winners) and a welfare loss to the others (the Losers). These problems are typical in a number of settings, such as climate action,...