There's no telling how much an economic-stimulus bill Gov. Corzine is expected to sign into law within weeks will increase or decrease the state's bottom line.

A fiscal analysis of the bill by the nonpartisan Office of Legislative Services dated Tuesday, after the bill received final legislative approval, concludes that potential costs and revenues are "indeterminate."

The executive branch, which is supposed to conduct a fiscal analysis whenever a bill may increase or decrease state or local expenditures or revenues, did not file an analysis of the bill.

What's clear is that the amounts involved are substantial.

The legislation would allow some developers to receive up to 75 percent of new tax revenues created by their projects for up to 20 years, and it would put a moratorium on a 2.5 percent nonresidential-development fee intended to build affordable housing.

Other provisions include expanding a program to give companies tax credits for investing in capital projects and bringing jobs close to mass-transit stations in cities including Camden, and giving certain manufacturing facilities a break on energy taxes.

Lawmakers in both houses of the Legislature approved the omnibus bill on June 25, just two weeks after it was introduced. Supporters argued it needed to be approved quickly, before the Legislature recessed for the summer, to help stimulate the economy.

Sen. Raymond Lesniak (D., Union), a sponsor of the Senate version of the bill, said he believed it would spur billions of dollars of investment and create tens of thousands of jobs. He has been referring to the bill as "the most powerful economic-growth tool on the planet."

Assembly Speaker Joseph Roberts Jr. (D., Camden), also a sponsor of the bill, said the "multi-faced effort sends the clear message that New Jersey is open for business and looking to the future."

But critics worry that the law will divert critical revenues at a time when they are most needed, and that it could eventually cost state and town governments billions of dollars.

If signed into law, the economic stimulus would allow developers to reap millions, if not billions, of dollars.

An earlier version of the bill would have refunded developers about $19 million in fees intended to build affordable housing.

But after critics argued that refunding those fees would not do anything to spur development, the bill was amended so that developers would be refunded only about $6 million, estimated Staci Berger, director of advocacy and policy for the Housing and Community Development Network of New Jersey.

Under the bill that was approved, a new Wal-Mart in Vineland, Cumberland County, is expected to receive a refund for $357,110 in affordable-housing fees, for example, Berger said.

Jeff Tittel, director of the New Jersey chapter of the Sierra Club, estimated that the affordable-housing-fee moratorium alone could mean tax breaks totaling $90 million for two of the biggest development projects under construction in the state: $50 million for Meadowlands Xanadu, a mammoth sports, entertainment and shopping complex in Bergen County, and $40 million for the new Giants Stadium.

Much smaller projects also stand to benefit, including a proposed office complex of seven buildings on land owned by Princeton University and a new Sam's Club being built in Edison, Berger said.

The bottom line, said Tittel, is that there has been no analysis "to determine the full cost the taxpayers will pay for these open-ended giveaways."

"There also has been no evaluation as to whether the developers even need this money or if it will just enable them to increase profits at the expense of the state's taxpayers," he added. "If developer profits are reaped as a result of this bill, there's no payback to taxpayers, unlike the federal stimulus bill."

Under the legislation, it's up to the state treasurer to determine whether public assistance to projects will result in net benefits to the state. The treasurer and the Economic Development Authority would decide jointly whether to give a developer a grant.

Lesniak argued that the provision that would allow developers whose proposals meet certain criteria to receive a grant for up to 75 percent of the new tax revenues generated by their projects for up to 20 years can only help to boost tax revenues, because it is intended only for developments that would not otherwise take place.

"Without this incentive financing, nothing happens," Lesniak said during a committee discussion of the bill. "Without this incentive financing, you're giving away nothing. You're giving away ice in the wintertime."

At a speech to New Jersey Business and Industry's Economic Development Forum on Tuesday, Lesniak said the stimulus bill would "raise from the ashes redevelopment of the former Burry Biscuit site on Newark Avenue that stalled due to an inability to finance its parking deck."

Other stalled projects in Elizabeth that would get a jump-start, Lesniak said, include a major retail development on Routes 1 and 9, an additional 100,000 square feet of retail construction near the Jersey Gardens Mall, and commercial developments in the Elizabethport, Bayway, and Elmora sections of the city.

Those and other projects would result in an additional quarter-billion dollars of investment and 2,000 new jobs in Elizabeth alone, Lesniak said.

But it remains unclear whether the public will ever know how much tax revenue the state and towns would forgo to generate such benefits.

Unlike most states, New Jersey does not keep track of such tax exemptions. The liberal think tank New Jersey Policy Perspective has for years argued that the state should track such so-called tax expenditures. Most states, including Pennsylvania and New York, make such information available. "The Legislature has no idea how much this is going to cost, how much developers might take advantage" of the law, said Naomi Bressler, a policy analyst with New Jersey Policy Perspective. "If municipalities throughout the state take advantage of this, it would be a significant revenue loss."

Contact staff writer Adrienne Lu at 609-989-8990 or alu@phillynews.com.