Cities with the highest proportion of likely spenders include San Francisco, Washington DC, Seattle, San Diego, Denver, Austin, Salt Lake City, Cincin

Americans are spending less; no surprise there. Figures out this week from the Commerce Department's Bureau of Economic Analysis show that in April overall consumer spending was down 0.1% from the month before. People are now saving 5.7% of their disposable income, the most since 1995 and a cosmic increase from the zero-savings days of just a few years ago.

Yet those numbers are far from the whole story. People aren't cutting back equally in all corners of the country; there are many undercurrents to our newfound national thriftiness. (Read about the best way to save even more.)

For instance, which city do you think has a greater percentage of people who are more likely to be shopping right now: Detroit or Birmingham, Ala.? Detroit, home of the bankrupt auto industry, or Birmingham, the decently moneyed Sunbelt metropolis? The answer: Detroit.

That's according to a new study by the data and analytics firm Acxiom. By collecting data on consumer characteristics and spending habits, Acxiom devised a system for categorizing people into groups that are more likely to spend their disposable income and those that aren't.

The cities with the highest proportion of likely spenders include San Francisco, Washington, Seattle, San Diego, Denver, Austin, Salt Lake City, Cincinnati, Norfolk and Jacksonville. The spots with the lowest proportion include Pittsburgh, Nashville, Tampa, St. Louis, Indianapolis, Little Rock, Knoxville, Tulsa, Fresno and Mobile.

How does Acxiom figure who is a "likely spender"? First, it asks. Monthly surveys by BIG Research, a separate company, inquire about how people's shopping habits have shifted and how changes — like gas-price increases — might alter habits. Then Acxiom digs into it own database, one of the most formidable collections of consumer data in the world. (A Fortune magazine headline once read, "Never Heard of Acxiom? Chances Are It's Heard of You.") Acxiom tracks some 128 million households, compiling data on everything from credit-card transactions to newspaper subscriptions. Some 1,500 data fields go into the computer model, and out comes an opinion about who you are and what you're likely to do with your money. (See 10 things to buy during the recession.)

If you live in Austin or Los Angeles, that opinion is you're likely to go spend. If you live in New York City or Memphis, not so much. "There's no such thing as a homogeneous consumer," says Acxiom retail executive Jim Harold.

Nor is there such a thing as a homogeneous city — which helps to account for the Detroit metro area's (relatively) spend-happy ways. Acxiom figures that some 64% of people in Oakland County, Michigan, home to Chrysler headquarters, fall into demographic groups that are more likely to spend. In neighboring Lapeer County, that percentage is 41%. The national picture reflects the same lumpiness. In other words, there are plenty of people in the Rust Belt with tightened purse strings, just as you would expect — but in the aggregate, other pockets of the country have pulled back more. And while there are some links between potential spending and local unemployment rates and median income, the relationships aren't bulletproof. One group of people more likely to spend: middle-income urban families who care more about protecting the quality of their lifestyle.

There are spenders out there. Though for the time being, still more savers.