Mortgage refinance activity is down 36 percent from its peak in May, according to the Mortgage Bankers Association — a trend fueled largely by a hefty jump in interest rates. The MBA reports that the average interest rate for a 30-year, fixed-rate mortgage hit a 14-month high of 4.15 percent last week. The fact that many homeowners have yet to take advantage of generally low rates could keep refinance activity fairly strong, even if at a slower pace, economists and lenders say. Forecasts from late last year predicted strong home sales but a sharp drop in mortgage refinance activity. Michael Lewis is Managing Editor at the National Notary Association.