EDITORIAL The next battle for San Francisco's future will be fought in significant part in what the Planning Department calls the eastern neighborhoods — South of Market, the central waterfront, the Mission District, Potrero Hill, and Showplace Square. That's where planners want to see some 29,000 new housing units built, along with offices and laboratories for the emerging biotech industry that's projected to grow on the outskirts of the UCSF Mission Bay campus.

On March 28 the Planning Department released the final draft of a socioeconomic impact study of the area, which, with 1,500 acres of potentially developable land, is one of San Francisco's last frontiers.

For a $50,000 report, the study doesn't really say much. It puts an overall rosy glow on a zoning plan that will lead to widespread displacement of blue-collar jobs and dramatically increased gentrification. And it fails to answer what ought to be the fundamental questions of anything calling itself a socioeconomic study.

But within the 197-page document are some stunning facts that ought to give neighborhood activists (and the San Francisco supervisors) reason to doubt the entire rezoning package.

On one level it's hard to blame Linda Hausrath, the Oakland economist who did the study: the premise was flawed from the start. The study considers only two possibilities — either the eastern neighborhoods will be left with no new zoning at all or the Planning Department's zoning proposal will be implemented. Her conclusion, not surprisingly, is that the official city plan offers a lot of benefits. That's hard to argue: the current zoning for the area is a mess, and much of the most desirable land is wide open for all sorts of undesirable uses.

But there are many, many ways to look at the future of the eastern neighborhoods beyond what the Planning Department has offered. Neighborhood activists in Potrero Hill have their own alternatives; so do the folks in the Mission and South of Market. There are a lot of ways to conceive of this giant piece of urban land — and many of them start and end with different priorities than those of the Planning Department.

Two key issues dominate the report — housing and employment in what's known as production, distribution, and repair, or PDR, facilities. PDR jobs are among the final remaining types of employment in San Francisco that pay a decent wage and don't require a college degree. The city had 95,000 of these as of 2000 (the most recent data that the study looks at), and 32,000 of them were in the eastern neighborhoods.

Almost everyone agrees that PDR jobs are a crucial part of the city's economic mix and that without them a significant segment of the city's population will be displaced. "There are two ways to drive people out of San Francisco," housing activist Calvin Welch says. "You can eliminate their housing or eliminate their jobs."

The city's rezoning plan seeks to protect some PDR uses in a few parts of the eastern neighborhoods. But many of the areas where the warehouses, light industrial outfits, and similar businesses operate will be zoned to allow market-rate housing — and that will be the end of the blue-collar jobs.

When you build market-rate housing in industrial areas, the industry is forced out. That's already been proved in San Francisco; just remember what happened in ...