The Subprime Virus.

We examine the correlation between prime mortgage default risk and the introduction of subprime mortgages in a local area. We motivate our analysis with a model of a default contagion effect that spreads the effect of a mortgage foreclosure from one property to surrounding properties. Through numerical analysis, we demonstrate the effect of subprime mortgage originations to the risk of prime mortgages. Finally, we offer empirical support for our model by examining the spatial variation in MSA prime mortgage default rates and the level of subprime mortgage activity. [ABSTRACT FROM AUTHOR]