The city has dozens of community-based nonprofit development organizations that operate largely out of the public eye, but a new study makes a compelling case for using them more often to bolster Philadelphia neighborhoods.

By documenting a two-decade track record of helping to create nearly 12,000 jobs, boosting city revenue by $28 million, and raising property values by $680 million through antiblight initiatives that included home construction and rehabilitation and commercial-corridor improvements, the report released Wednesday gives bragging rights to the groups known as CDCs - for community development corporations.

Surveying the work of 44 community-based groups, consultants hired by the nonprofits' trade association estimate CDCs have kicked in $3.3 billion to the city economy since 1992. Much of that activity stemmed from 1,500 construction projects, but the groups also provide housing counseling, job training, energy conservation, and after-school programs.

Just as public policy can be shaped by recent economic impact studies of the city's cultural sector, the CDC analysis offers City Hall further proof that these groups are worthy partners for public and private investment. Indeed, Mayor Nutter hails them for getting bangs for the buck.

On average, CDCs create 500 to 600 new homes yearly, forming a solid base for such improvement efforts. In a down economy, when market-rate developers have scaled back, the CDCs' role is even more important to leverage private funds.

With the city's CDC business tax credit, the community developers have received millions of dollars in support from firms pledging annual contributions of as much as $100,000. These partnerships, of course, mean the city agrees to forgo some $3 million in annual revenue. So while demand outstrips the supply of these credits, the city has had to trim the benefits of late.

When the economy improves, it would be a smart move to expand the CDC tax program. Not only does it appear to be a good strategic investment that fuels neighborhood improvement and strengthens the tax base, but the links with businesses can mean other positive spin-offs.

Another key strategy for expanding support for CDCs' work could be for Nutter to ensure close cooperation with the city's land bank, now being developed to find productive uses for vacant properties around the city. Beyond being able to deliver on their own projects, CDCs often pave the way for larger-scale investments that help developing neighborhoods move forward.