We propose an extension of Harsanyi's Impartial Observer Theorem based on the representation of ignorance as the set of all possible probability distributions over individuals. We obtain a characterization of the observer's preferences that, under our most restrictive conditions, is a convex...

Individuals save for their old days, but not all of them enjoy the old age. This paper characterizes the optimal capital accumulation in a two-period OLG model where lifetime is risky and varies across individuals. We compare two long-run social optima: (1) the average utilitarian optimum, where...

Individuals save for their old days, but not all of them enjoy the old age. This paper characterizes the optimal capital accumulation in a two-period OLG model where lifetime is risky and varies across individuals. We compare two long-run social optima: (1) the average utilitarian optimum, where...

This article determines the conditions under which theSouthern countries should act together, or separately, while negotiating with the North about climate change policy and about the conditions for future Southern engagement. The paper models the international negotiations with complete and...

We propose a mechanism for resolving bargaining problems.The mechanism allows two players to make a sequence of simultaneous propositions. At any step, as long as the players have not reached an agreement, they can choose to implement a lottery between the different propositions. In this aspect,...

A local public goods game in weighted and directed networks is analyzed. Individual efforts are imperfect substitutes, players' preferences are heterogeneous and local externalities are non-uniform and asymmetric. Sufficient conditions under which the game admits a unique equilibrium are...

One answers to an open question of Herings et al. (2008), by proving that their fixed point theorem for discontinuous functions works for mappings defined on convex compact subset of $\R^n$, and not only polytopes. This fixed point theorem can be applied to the problem of Nash equilibrium...

In recent years, there has been a rising concern about the policy of major search engines, and more specifically about their ranking in so-called organic results corresponding to keywords searches. The associated proposition is that their behavior should be regulated. The concern comes from...

We deal with the problem of outsourcing the debt for a big investment, according two situations: either the firm outsources both the investment (and the associated debt) and the exploitation to a private consortium, or the firm supports the debt and the investment but outsources the...

One answers to an open question of Herings et al. (2008), by proving that their fixed point theorem for discontinuous functions works for mappings defined on convex compact subset of a Euclidean space, and not only polytopes. This rests on a fixed point result of Toussaint