PMI Mortgage released its Summer 2007 U.S. Market Risk Index(SM), which ranks the nation's 50 largest metropolitan statistical areas (MSAs) according to the likelihood that home prices will be lower in two years. The enhanced index, which gives additional weight to an area's recent price volatility, shows a shift in risk toward Florida and California, as well as certain areas of the southwest. For the 50 largest MSAs, the average score, weighted by population, was 346, translating into a 34.6 percent chance that prices will be lower in two years.