Rising home prices and interest-rate trends continue to decrease purchase-mortgage affordability for potential homebuyers. However, industry analysts note that mortgage affordability is still historically high and could soon improve. The 20-city S&P/Case-Shiller home price index increased by 1.8 percent in July compared with the previous month, according to the latest data released this week. On a year-over-year basis, the index was up by 12.4 percent. The home-price gains indicate a ...