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 consider a natural generalization of Jackson and Wolinsky's (J Econ Theory 71:44- 74, 1996) connections model where the quality or strength of a link depends on the amount invested in it and is determined by a non-decreasing function of that amount. The information that the nodes receive...

In this paper we address several issues related to collective dichotomous decision-making by means of quaternary voting rules, i.e., when voters may choose between four actions: voting yes, voting no, abstaining and not turning up-which are aggregated by a voting rule into a dichotomous...

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...

We culminate 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 particular type of...

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 information that the nodes receive through the network. First, the structures of efficient...

This paper studies the connections model (Jackson and Wolinsky, 1996) when nodes may have different values. It is shown that efficiency is reached by a strongly hierarchical structure that we call strong NSG-networks: Nested Split Graph networks where the hierarchy or ranking of nodes inherent...

In this paper we measure the effect of the quota on the difficulty of making decisions in the EU-25 Council with the weights agreed upon in the Treaty of Nice. We compute the probability of a proposal being rejected in the Council. This probability depends on the voting rule (and therefore on...

In this paper we revise the probabilistic foundations of the theory of the measurement of 'voting power' either as success or decisiveness. For an assessment of these features two inputs are claimed to be necessary: the voting procedure and the voters' behavior. We propose a simple model in...