U.S. home prices are at their least affordable since 2008, according to a new study that found that home affordability is below historic averages in both Sarasota and Manatee counties. The study measures home affordability by comparing a region's average wages with its median home sales prices. Sarasota County's affordability index was estimated at 89, less than the historic average of 100, while Manatee County's index was estimated at 95. That means both counties are facing historically low levels of housing affordability. The study was conducted by ATTOM Data Solutions.