Despite claims to the contrary, credit unions do a poorer job serving low- and middle-income people than banks, a new government report says.

Or does it?

Credit unions don't think so, and they're armed with their own numbers.

And so the fight continues.

The U.S. Government Accountability Office, at the behest of the House Ways and Means Committee, took on one of the key points of contention in the oft-acrimonious battle between banks and credit unions, in Utah and across the nation: whether credit unions' tax-exempt status should be maintained, and specifically, whether they remain true to the industry's legally stated mission to serve people of "modest means."

Its findings, released this month, highlighted marked growth among so-called "community" chartered federal credit unions, which, unlike those designated to serve a particular group, serve a "well-defined local community, neighborhood or rural district." (Bank advocates say credit unions use this charter to vastly expand their operating areas.) At the same time, the report suggested, credit unions lagged behind similarly-size banks in their efforts to serve the poor.

The number of federally chartered credit unions fell from 2000 to 2005, the GAO found, while the industry's assets grew by about $140 billion. This was in no small part due to the growth of federal "community chartered" credit unions, the report said, which saw their assets nearly quadruple during that period, from $27.1 billion to $104.4 billion.

The GAO noted that the industry, via the National Credit Union Administration, has taken steps to make credit union services available to people of "modest means," like allowing credit unions to branch into "underserved areas" beyond a charter's designated boundaries. However, it struggled to find out to what extent credit unions actually serve the poor.

"Information that directly measures the income levels of credit union members continues to be limited," the report said.

An underlying empirical problem: There is no firm definition of "modest means," nor any standardized way of measuring that particular variable. So, for its study, the GAO used the Federal Reserve's 2004 Survey of Consumer Finances — what it called "the most recent available information on the income of credit union members" — and found that "credit unions continued to lag behind banks in the percentage of their customers or members that were of low- and moderate-income households."