EDITORIAL You read the academic journals these days, or peruse economic-development Web sites, and everyone seems to be talking about sustainable urban economics. It's as if the mantra that was first put forward by Jane Jacobs, David Morris, and a few others a quarter century ago is very much in the mainstream today: Cities function best with diverse economies dominated by locally owned businesses, with money circuutf8g within the community. Cutting-edge restaurants talk about serving locally grown food. Beverage savants want local beer and wine. Just about everyone — including the mayor and the San Francisco Chamber of Commerce — wants to participate in a program called Shop Local.

It's a wonderful, encouraging trend — but if it's going to make any real difference in this city, it has to become a lot more than lip service. Consider: •Just as Mayor Newsom was proudly signing on to a Shop San Francisco program, the mayor and the supervisors were busy approving plans to allow Home Depot — an anticompetitive out-of-town corporation that destroys local small business and undermines the entire concept of a strong local economy — to build a giant store on Bayshore Boulevard.

 •It's taken legal action by Sue Hestor and the neighborhood leaders to derail (for now) the mayor's plans to build high-end condos all over the eastern neighborhoods — threatening hundreds of locally owned businesses.

•Downtown business leaders and the groups they fund still push for policies that hurt most of the businesses in the city — and too many small-business people still go along.

Here's the reality: Supporting small businesses — and moving San Francisco toward a sustainable economy — requires a lot more than a slogan. The people who are behind the Shop Local movement know that. They're promoting a wide range of national and local policies designed to change not only attitudes but the direction of public policy.

San Francisco, a progressive city known for its wonderful, lively, unique neighborhoods, ought to be a national leader in the battle. But others (Philadelphia, for example) are moving way ahead. This city is still stuck in an ancient (and regressive) economic mind-set.