Humans cooperate a great deal in economic activity, but our two major models of equilibrium – Walrasian competitive in markets and Nash in games – portray us as only non-cooperative. In earlier work, I have proposed a model of cooperative decision making (Kantian optimization); here, I embed...

This working paper extends the methodology of non-smooth affective portfolio theory (APT) for eliciting (IR)rational preferences of investors endowed with continuous quasilinear utility functions, where assets are portfolios of risky and ambiguous state-contingent claims. The elicitation is a...

Although evidence accrues in biology, anthropology and experimental economics that homo sapiens is a cooperative species, the reigning assumption in economic theory is that individuals optimize in an autarkic manner (as in Nash and Walrasian equilibrium). I here postulate an interdependent kind...

Although evidence accrues in biology, anthropology and experimental economics that homo sapiens is a cooperative species, the reigning assumption in economic theory is that individuals optimize in an autarkic manner (as in Nash and Walrasian equilibrium). I here postulate a cooperative kind of...

We show that in almost every economy with separable externalities, every competitive equilibrium can be Pareto improved by a package of anonymous commodity taxes that causes prices to adjust and markets to reclear at different levels of individual consumption. This constrained suboptimality of...

Economic theory has focused almost exclusively on how humans compete with each other in their economic activity, culminating in general equilibrium (Walras) and game theory (Nash). Cooperation in economic activity is, however, important, and is virtually ignored. Because our models influence our...

We show that in almost every economy with separable externalities, every competitive equilibrium can be Pareto improved by a package of anonymous commodity taxes that cause prices to adjust and markets to reclear at different levels of individual consumption. The argument can be extended to...

We prove the existence of monetary equilibrium in a finite horizon economy with production. We also show that if agents expect the monetary authority to significantly decrease the supply of bank money available for short term loans in the future, then the economy will fall into a liquidity trap...

One measure of the health of the Social Security system is the difference between the market value of the trust fund and the present value of benefits accrued to date. How should present values be computed for this calculation in light of future uncertainties? We think it is important to use...

The 1996 PRWORA reform introduced time limits on the receipt of welfare in the United States. We use variation by state and across demographic groups to provide reduced form evidence showing that such limits led to a fall in welfare claims (partly due to "banking" benefits for future use), a...