 His 1999 "Journal of Political Economy", with John Y. Campbell, develops a representative agent model with nonlinear habits that matches the high and volatile risk premium on stocks, the predictability of stock returns, etc.In several articles (1991 "The Journal of Finance", 1996 "Journal of Political Economy"), he develops and tests a "production-based asset pricing model" based on the q-theory of investment.In two 1992 articles, Cochrane emphasized some features of asset prices which are difficult to account for, such as the predictability of equity returns, and the longterm equity premium.