"Even though wavering U.S. stock and job markets gave consumers the jitters during the summer, they kept spending freely on cars and housing, and a new consumer-spending index produced by Deloitte Research helps to explain why.</br></br>Carl Steidtmann, Deloitte's chief economist, says economists spend too much time watching wiggles in monthly consumer-confidence measures -- which have recently slipped -- to try to gauge the outlook for spending. The more important indicator of the outlook for spending, he says, is long-term trends in the actual cash going into and out of people's pocketbooks. His index of cash flow is pointing up -- thanks to factors such as tax cuts, wage gains and increases in home prices -- suggesting that spending could strengthen, at least for the next few months.</br></br>""Consumers are wallowing in cash,"" says Mr. Steidtmann. Deloitte Research is a unit of Deloitte Touche Tohmatsu, an accounting and consulting partnership.</br></br>Data released by the government Friday underscored this argument. The University of Michigan said its monthly index of consumer confidence fell in August to 87.6 from 88.1 in July. A separate measure of confidence produced by the Conference Board was also down in August.</br></br>But consumer spending picked up after slowing down during the spring. In July, consumption rose 1% from the previous month, the Commerce Department said, largely because of a new outburst of spending on cars backed by 0% financing deals. Spending in July grew at a 6.7% annual rate from the second quarter, according to calculations by UBS Warburg."