A new study has found that legalising same-sex marriage in Hawaii could boost tourism by $217 million (£141 million) over three years.

The study from the University of Hawaii’s Economic Research Organisation found that state and local general exise tax revenues could be boosted by $10.2 million (£6.64 million) between 2014 and 2016.

Previous estimates at how much changing the law could bring in for the tourism industry had been less specific because the two cases in the US Supreme Court were still pending.

Sumner LaCroix, the author of the study, said the recent decisions in the Defense of Marriage Act (DOMA) case, which allowed federal benefits for same-sex married couples, and the Proposition 8 case in California, which eventually led to the rejection of a law blocking same-sex marriage, had given a clearer picture of what lies ahead, but that Hawaii would need to act quickly in order to take advantage of the potential gains.

“If Hawaii waits to adopt same-sex marriage, it will not realise these gains,” LaCroix writes in the analysis. “They will be lost forever, diverted to other states that recognise marriage equality.”

Since the Supreme Court rulings, equal marriage supporters have been pushing for a special session in Hawaii to push for same-sex marriage, but legislators in the House and Senate this week said they did not have the support needed to call themselves back into session.

A proposed constitutional amendment failed at House committee earlier this year, and a Senate resolution calling for more study on the issue passed.

The Legislature will convene its regular session in January.

According to the study, most of the extra visiting spending would come from couples from other US states with equal marriage law who might plan a destination wedding, or a honey moon in Hawaii.

It estimated that $166 million (£108 million) would be spent on honeymoons and marriage ceremonies. LaCroix estimated that almost 2,000 gay and lesbian couples living in Hawaii could be married by 2016.