Consider an economy in which the underlying security returns follow a linear factor model with constant coeffcients. While portfolios that invest in these securities willin general, have a linear factor structure, it will be one with time-varying coeffcients. However, under certain assumptions...

This article proposes a rational model to demonstrate that firm-specific risks can be priced in the equilibrium and can generate asset pricing anomalies such as momentum. In general, business risks at both the market level and firm level can affect a firm's investment decisions, and a firm...

This paper proposes a simple back testing procedure that is shown to dramatically improve a panel data model's ability to produce out of sample forecasts. Here the procedure is used to forecast mutual fund alphas. Using monthly data with an OLS model it has been difficult to consistently predict...