A weekly index that is a leading indicator of home sales activity. The four-week moving average of the indices, which includes indices for composites, purchases, refinancing, fixed mortgage rates, and adjustable mortgage rates, smoothes out the volatile weekly figures. Because many homebuyers apply for a mortgage before purchasing a home, the mortgage application purchase index is a leading indicator of future home sale activities and is an early gauge of economic strength. Refinancing activity is important because it often leads to increased levels of consumer spending. The data is timely, with a lag factor of only five days. However, the data is limited because it covers less than half of the U.S. residential mortgage market and the historical data goes back only to 1990. The Mortgage Bankers Association of America (MBAA) produces the data.