WASHINGTON (AP) â¿¿ The Commerce Department reports Friday on sales at retail chains and restaurants. Report to be released at 8:30 am EDT. RETAIL SALES UP: Economists forecast that retail sales rose 0.4 percent in August, double the July increase. AUTOS, HOUSING LIFT SPENDING: Americans have increased their spending at retail businesses in eight of the past nine months. But the gains have been gradual and largely concentrated in a few key areas. The best auto sales since before the recession have helped. And the housing recovery has lifted demand for building materials and home furnishings. CONSUMERS DRIVE ECONOMY: Retail sales are closely watched because they're the government's first report each month on consumer spending, which accounts for 70 percent of U.S. economic activity. Auto dealers are likely to report big sales gains. Car sales topped 16 million at an annual pace in August for the first time since November 2007, just before the recession began, according to company reports last week. Toyota, Ford, Nissan, Honda, Chrysler and General Motors all posted double-digit gains over last August. But many retailers have said in recent weeks that shoppers have been reluctant to fully open their wallets for back to school shopping. According to a tally of 10 retail chains by the International Council of Shopping Centers, sales rose 3.6 percent last month. That's down from a 6 percent increase a year ago. Job gains have been steady this year. But the pace of hiring has been too weak to rapidly lower the unemployment rate, which is 7.3 percent four years after the Great Recession officially ended. With millions of Americans still unemployed, companies have little incentive to boost pay. Americans are seeing little growth in their wages at the same time they are grappling with higher taxes. The combination has limited their spending power, and kept the economy from accelerating.