New Jersey could boost its economy by more than half a billion dollars over the next three years by promptly legalizing same-sex marriage, a California law professor told a state commission yesterday.

Brad Sears, executive director of the Williams Institute at UCLA School of Law, said gay weddings alone would pump $248 million into New Jersey's economy under a "very conservative" economic analysis. He said additional spending on gifts, overnight hotel stays by visiting friends and other items could boost the total to "a half billion dollars plus" over the next three years.

Sears testified before the New Jersey Civil Union Review Commission, which is exploring the economic impact of legalizing gay marriage. He said by legalizing only civil unions for same-sex couples, as it did in February 2007, New Jersey had incurred "all the costs without getting the main benefit" -- spending on wedding celebrations.

John Tomicki, chairman of the N.J. Coalition to Preserve and Protect Marriage, said that argument could justify polygamy.

"To take that reasoning further you should be able to marry 10 people at a time and that would cause even larger receptions," Tomicki said in a telephone interview. "The logic is rather silly."

But Marcia Van Wagner, a deputy comptroller for New York City, told the commission, "While the civil rights justification for civil unions and marriage equality is persuasive alone, there is a strong economic argument for legally recognized gay unions as well."

Last year the New York City Comptroller's Office calculated allowing gays to marry would have a net boost on that city's economy of $142 million in the three years following legalization.

That analysis found gay marriage would cost New York City employers $33 million in health insurance premiums for same-sex spouses, but that would be more than offset by spending on weddings. It calculated those weddings -- many among same-sex couples from New Jersey and other states traveling to the Empire State to wed -- would pump $175 million into New York City's economy.

Sears said New Jersey risks losing gay wedding business by waiting to legalize same-sex marriage. Were it to do so promptly, he said, it could expect about 22,000 New York same-sex couples to come to the Garden State to be wed and spend about $66 million.

Those couples, and even many New Jersey couples, might instead get married in California, which began performing same-sex weddings this week, Sears said. The only other state to recognize same-sex marriage is Massachusetts, which will not wed a couple if doing so would be illegal in their home state.

Sears said Connecticut might soon recognize same-sex marriage and deprive New Jersey of the "East Coast advantage" it could gain by moving quickly.

New Jersey Civil Rights Director J. Frank Vespa-Papaleo, who chairs the commission, said, "It sounds like you're saying today: Time is of the essence." Sears agreed it is.

"We should be asking the question: Why should civil rights wait one day when it's, one, a human rights issue, and two, a fiscal issue," Vespa-Papaleo added.

The commission was formed to advise the New Jersey Legislature, which has bills before it that would legalize same-sex marriage. The commission issued an interim report in February finding civil unions have not lived up to their promise of providing all the benefits of marriage by another name.

Robert Schwaneberg may be reached at (609) 989-0324 or rschwaneberg@starledger.com.