The Mortgage Bankers Association said Wednesday morning that its Market Composite Index of mortgage application activity rose 2.9 percent to 674.4 for the week ended May 9; applications remained off 1.1 percent compared to year-ago activity, the MBA said. The application index is calibrated to March 16, 1990; a reading of 567.0 means that application activity was roughly 5.7 times greater than when the index was first established. Primarily driving the increase were refinance applications, the MBA said, which rose 6.5 percent from the previous week; purchase applications, typically of more interest to economists, fell 0.7 percent on a seasonally-adjusted weekly comparison basis. Some economists and industry experts have suggested that the MBA index is prone to overstatement by counting multiple applications from the same borrower -- particularly for refinancing activity -- which may more directly indicate credit distress than market sentiment. Housing Wire covered the issue in a report published last week. Refinance share of mortgage application activity jumped to 48.7 percent, compared to 47.1 percent one week earlier; ARM share of activity jumped to 8.3 percent, up sharply from 6.8 percent one week earlier. The MBA said that mortgage rates eased last week somewhat, reporting that the average rate on a fixed 30-year mortgage fell 9 basis points to 5.82 percent. Formal rate reports from Freddie Mac (FRE) and are set to be released Thursday. For more information, visit Disclosure: The author held no positions in FRE when this story was originally published. HW reporters and writers follow a strict disclosure policy, the first in the mortgage trade.