The Labor Department said on Wednesday its Consumer Price Index dropped 0.2 percent last month as a broad decline in energy prices offset increases in food and shelter costs. Economists had expected consumer prices would be flat in August. “There is still enough slack in the economy to keep a tight lid on price increases, which should support the view of those within the Fed arguing in favor of patience before the first rate hike,” said Anthony Karydakis, chief economic strategist at Miller Tabak in New York.