By Pat Loeb

PHILADELPHIA (CBS) — Philadelphia has long counted on Community Development Corporations for housing and commercial improvements at the neighborhood level. Now, a local umbrella group has calculated the dollar value of their work.

The report by the Philadelphia Association of CDC’s says the groups have collectively invested $2.2 billion locally over the last 20 years — a combination of federal, state and city urban development money and some private financing. But executive director Rick Sauer says that has generated $3.3 billion in economic development.

“This report shows the tremendous value and impact that CDC’s have had,” he says, “and why they’re such an important neighborhood anchor in facilitating neighborhood revitalization.”

Not that it’s been a flawless model. There have been cases of bankruptcy, substandard work and alleged political favoritism, but there have also been resounding successes, such as Park West and Aramingo Crossing shopping centers.

“We want to hold up what is working well, Sauer says, “so people realize this is a smart investment with a good return.