This paper presents a model in which the realizations of stochastic tax and depreciation rates determine both the level and growth rate of output: externalities to investment - learning by watching - are characterized by diminishing returns, yielding a nonlinear "technical progress function"....

This paper investigates why, in October 1987, almost all stock markets fell together despite widely differing economic circumstances. The idea is that "contagion" between markets occurs as the result of attempts by rational agents to infer information from price changes in other markets. This...

Empirical tests of the life cycle model have focused on its implications for the level of a household's total net worth and paid little attention to changes in portfolio composition over the life cycle. In this paper, we examine a new survey of the asset holdings of 6,010 U.S households and show...