It is sometimes argued that an increase in stock market volatility raises required stock returns, and thus lowers stock prices. This paper modifies the generalized autoregressive conditionally heteroskedastic (GARCH) model of returns to allow for this volatility feedback effect. The resulting...

It is sometimes argued that an increase in stock market volatility raises required stock returns, and thus lowers stock prices. This paper modifies the generalized autoregressive conditionally heteroskedastic (GARCH) model of returns to allow for this volatility feedback effect. The resulting...

"This paper shows that the stock market downturns of 2000-2002 and 2007-09 have very different proximate causes. The early 2000's saw a large increase in the discount rates applied to corporate profits by rational investors, while the late 2000's saw a decrease in rational expectations of future...