The optimism needle is stuck on caution for Michigan retailers. The latest Michigan Retail Index found a solid 66 percent of the state's retailers projecting increased sales for fall and the early part of the holiday shopping season. But that number has remained the same since June - in contrast to years past, when positive expectations continued building from June through August and reached well into the 70s by late summer.The Index, a joint project of the Michigan Retailers Association (MRA) and Federal Reserve Bank of Chicago, found that the level of optimism remained constant despite an uptick in August sales. Forty-nine percent of retailers reported increased sales over the same month last year, up from 45 percent in July. Another 14 percent reported no change, while 37 percent reported decreased sales."A note of cautious optimism for the fall is no surprise given thelackluster sales growth much of this year," said Larry Meyer, CEO of MRA and a former director of the Michigan Department of Commerce."Back-to-school shopping provided some boost, but not enough.consumersand retailers could have benefited from a two-week, late-summer sales tax holiday on apparel and shoes -- which we'll continue to push for in the Michigan Legislature in time for implementation next year."The Michigan Retailers Association is the unified voice of retailing in Michigan and the nation's largest state trade association of general merchandise retailers. MRA's more than 5,500 retail business members operate more than 12,000 stores across the state.