Martin Shubik Publications

We criticize the R.E.E. approach to asymmetric information general equilibrium because it does not explain how information gets “into” the prices. This leads to well-known paradoxes. We suggest a multiperiod game instead, where the flow of information into and out of prices is explicitly modeled. In our game Nash equilibria (N.E.) (1) generalize Walrasian equilibria to asymmetric information; (2) exist generically; (3) eliminate pure speculation; (4) allow prices to reveal information and markets to become more efficient over time; (5) are consistent with the weak efficient markets hypothesis that tracking past prices is not profitable; (6) yet always lead to higher utility for better informed agents (such as experts). Throughout the paper we use one concrete game. In the last section we prove that there are a broad range of games that would have the same properties.

A general model of a coalition production economy allowing set-up costs, indivisibilities, and non-convexities is developed. It is shown that for all sufficiently large replications, approximate cores of the economy are non-empty.

Sufficient conditions are demonstrated for the non-emptiness of asymptotic cores of sequences of replica games, i.e., for all sufficiently large replications, the games have non-empty approximate cores and the approximation can be made arbitrarily “good”. The conditions are simply that the games are superadditive and satisfy a very non-restrictive “per-capita” boundedness assumption (these properties are satisfied by games derived from well-known models of replica economies). It is argued that the results can be applied to a broad class of games derived from economic models, including ones with external economies and diseconomies, indivisibilities and non-convexities. To support this claim, in Part I applications to an economy with local public goods are provided and in Part II, to a general model of a coalition production economy with remarkably few restrictions on production technology sets and with (possibly) indivisibilities in consumption. Additional examples in Part I illustrate the generality of the result.

Sufficient conditions are demonstrated for the non-emptiness of asymptotic cores of sequences of replica games, i.e., for all sufficiently large replications, the games have non-empty approximate cores and the approximation can be made arbitrarily “good”. The conditions are simply that the games are superadditive and satisfy a very non-restrictive “per-capita” boundedness assumption (these properties are satisfied by games derived from well-known models of replica economies). It is argued that the results can be applied to a broad class of games derived from economic models, including ones with external economies and diseconomies, indivisibilities and non-convexities. To support this claim, in Part I applications to an economy with local public goods are provided and in Part II, to a general model of a coalition production economy with remarkably few restrictions on production technology sets and with (possibly) indivisibilities in consumption. Additional examples in Part I illustrate the generality of the result.

A general model of a coalition production economy allowing set-up costs, indivisibilities, and non-convexities is developed. It is shown that for all sufficiently large replications, approximate cores of the economy are non-empty.