This paper examines the different factors that have contributed to the subprime mortgage credit crisis: the search for yield enhancement, agency problems, lax underwriting standards, failure by the rating agencies to identify a changing environment, poor risk management by financial...

Encompassing a very broad family of ARCH-GARCH models we show that heteroskedasticity, already well documented for the US market, is a worldwide phenomenon. The AT-GARCH (1,1) model, where volatility rises more in response to bad news than to good news, and where news is considered bad only...