The rise in interest rates that started in May has yet to have a significant impact on the purchase-mortgage market, according to the Campbell/Inside Mortgage Finance HousingPulse Tracking Survey. However, analysts say higher interest rates and rising home prices will constrain housing affordability. The non-cash share of home-purchase financing increased for the sixth consecutive month in August to 72.8 percent, based on the three-month moving average. The trend has been driven by a shift from investor purchases of distressed properties to activity among current homeowners and non-distressed properties. The non-distressed market showed...