We introduce the following basic voting method: voters submit both a “consensus” and a “fall-back” ballot. If all “consensus” ballots name the same option, it wins; otherwise, a randomly drawn “fall-back” ballot decides. If there is one potential consensus option that everyone...

In this paper we show how theorems of Borsuk-Ulam and Tucker can be used to construct a consensus-halving: a division of an object into two portions so that each of n people believe the portions are equally split. Moreover, the division takes at most n cuts, which is best possible. This extends...

As the Copenhagen Accord indicates, most of the international community agrees that global mean temperature should not be allowed to rise more than two degrees Celsius above preindustrial levels to avoid unacceptable damages from climate change. The scientific evidence distilled in the Fourth...

A formal framework for the treatment of hierarchical coalition formation and hierarchical agreements under both the bargaining and blocking approaches to coalition formation is introduced, and some first positive results on the possibility of full agreement and the efficiency of hierarchical...

Using Putnam’s two‐level game approach, we discuss the influence of domestic players that can veto the ratification of international environmental agreements on the breadth and depth of such treaties. We first show that in a symmetric Barrett‐type payoff model, veto-players can restrict...

We present typical scenarios and general insights from a novel dynamic model of farsighted climate coalition formation involving market linkage and cap coordination, using a simple analytical model of the underlying cost-benefit structure. In our model, the six major emitters of CO2 can link...

The expected number of pairwise comparisons needed to learn a partial order on n elements is shown to be at least /4 − (), and an algorithm is given that needs only /4 + () comparisons on average. In addition, the optimal strategy for learning a poset with four elements is presented