Tax-increment financing has taken its share of heat, especially in the suburbs, where the development tool has sometimes been abused.

A glaring example looms like the Tower of Babel over the Camp Horne exit on Interstate 279 in Ohio Township, where a wooded hill was declared blighted so local governments could help in building yet another shopping plaza -- in the North Hills, where plenty of developers put up shopping plazas without government help.

That, however, does not mean tax-increment financing is a bad idea. If used to help rebuild a truly blighted area or spur economic growth in a way that will actually boost the overall economy, TIFs -- which let counties, municipalities and school districts divert part of the anticipated increased tax receipts from the improved property to pay for part of its development -- can be wonderful tools.

A good example sits before City Council. The Urban Redevelopment Authority wants to use a TIF to provide $18 million to help PNC Financial Services Group build a $170 million skyscraper on Fifth Avenue Downtown, a project that is also getting $30 million in state grant money.

It's hard to imagine a project more suited to such help from future taxes it will generate. That the proposed site is "blighted" is depressingly obvious. It also will be tough to develop without public help, and Pittsburgh is fortunate to have PNC investing $122 million of its own money in the package. With the mix of offices, hotel rooms, condominiums and retail, the project will be a boost to the economic vitality of Downtown.

To be sure, the cost to the city, its public school system and Allegheny County would be substantial: 60 percent of the project's new property and parking taxes, or about $1.7 million a year for 20 years. But that's revenue that none of the government entities is collecting at the largely vacant and shabby-looking block now. The $1.15 million collected by the three taxing bodies on the new development would still be six times what they get from the space now. So, in a very real sense, there's nothing to lose.

The same argument was made for Mount Nebo Pointe, the TIF-assisted plaza that is bringing Target, Sam's Club and the already-open Sportsmen's Warehouse to Ohio Township. But that site is not far from similar shopping, including some of the same merchants -- which will compete for the same North Hills shoppers.

All of which argues that TIFs must be used selectively and judiciously. They can have real benefits and positive impact where development is truly needed and otherwise unlikely -- like the Fifth and Forbes corridor.