Many tests of asset pricing models address only the pricing predictions — but these pricing predictions rest on portfolio choice predictions which seem obviously wrong. This paper suggests a new approach to asset pricing and portfolio choices, based on unobserved heterogeneity. This approach...

Many tests of asset-pricing models address only the pricing predictions, but these pricing predictions rest on portfolio choice predictions that seem obviously wrong. This paper suggests a new approach to asset pricing and portfolio choices based on unobserved heterogeneity. This approach yields...

We study David Gale's (1963) economy using laboratory markets. Tatonnement theory predicts prices will diverge from an equitable interior equilibrium toward infinity or zero depending only on initial prices. The inequitable equilibria determined by these dynamics give all gains from exchange to...

Prices and quantities converge to the theoretical competitive equilibria in continuous, double auction markets. The double auction is not a tatonnement mechanism. Disequilibrium trades take place. The absence of any influence of disequilibrium trades, which have the capacity to change the...