We study a connections model where the strength of a link depends on the amount invested in it and is determined by an increasing strictly concave function. The revenue from investments in links is the value (information, contacts, friendship) that the nodes receive through the network. First,...

We complete the extension of the results on efficiency in the seminal connections model of Jackson and Wolinsky (1996), partially addressed in previous papers. In a model where both nodes and links are heterogeneous, we prove that efficiency is reached by networks with a unique non-trivial...

In this paper we study the effects of institutional constraints on stability, efficiency and network formation. More precisely, an exogenous "societal cover" consisting of a collection of possibly overlapping subsets that covers the whole set of players and such that no set in this collection is...

This paper connects two notions: Hart and Mas-Colell’s ‘potential’, related to the value of coalitional games, and Coleman’s earlier notion of ‘power of a collectivity to act’, related to the easiness to make decisions by means of a voting rule. Copyright...

Power indices are meant to assess the power that a voting rule confers a priori to each of the decision makers who use it. In order to test and compare them, some authors have proposed ‘natural’ postulates that a measure of a priori voting power ‘should’ satisfy, the violations of which...

In this paper we explore the noncooperative foundations of the bargaining power that a voting rule gives to each member of a committee that bargains in search of consensus over a set of feasible agreements under a voting rule. Assuming complete information, we model a variety of bargaining...

In a recent paper, we provide an interpretation of the Shapley-Shubik index as a measure of the 'bargaining power' that a voting rule gives to each member of a committee negotiating in search of consensus. It is assumed that negotiation takes place under the condition that every winning...