It is well known that ex post e¢ cient mechanisms for the provision of indivisible public goods are not interim individually rational. However, the corresponding literature assumes that agents who veto a mechanism can enforce a situation in which the public good is never provided. This paper instead considers majority voting with uniform cost sharing as the relevant status quo. E¢ cient mechani...

Techniques for the construction of dynamical Galaxy models should be considered essential infrastructure that should be put in place before GAIA flies. Three possible modelling techniques are discussed. Although one of these seems to have significantly more potential than the other two, at this stage work should be done on all three. A major effort is needed to decide how to make a model consis...

We characterize preferences over acts that can be represented by a utility function and a multiple–prior, such that an act f is preferred to act g if there is a prior under which the expected utility induced by f is higher than that induced by g. These preferences are referred to as justifiable preferences. We further introduce a generalized model of ambiguity that involves a collection of mult...

0.1. Preface. In 1963 Ya. G. Sinai [Sin(1963)] formulated a modern version of Boltzmann’s ergodic hypothesis, what we now call the “Boltzmann-Sinai Ergodic Hypothesis”: The billiard system of N (N ≥ 2) hard balls of unit mass moving on the flat torus T = R/Z (ν ≥ 2) is ergodic after we make the standard reductions by fixing the values of trivial invariant quantities. It took fifty years and the...

Many institutional investors periodically adopt an asset allocation policy that specifies target percentages of value for each of several asset classes. Typically a policy is set by a fund’s board after evaluating the implications of a set of alternative policies. The staff is then instructed to implement the policy, usually by maintaining the actual allocation to each asset class within a spec...

A voting protocol is said to be strongly participatory if for any player i and any strategy profile either the outcome is i‘s preferred one or i has a strategy which would ensure her a better outcome, and VNMstrategy proof if at any preference profile the set of sincere strategies of each player is a VNM-stable set. It is shown that the proportional lottery (PL) modular voting protocol is both ...