The Williams Institute, a UCLA think tank, and Credit Suisse have released a report that estimates the nationwide “economic boost” from marriage of same-sex couples could be as high as $2.6 billion.

“Same-sex couples and their out-of-town guests spend money to celebrate weddings,” Williams scholar M.V. Lee Badgett said in a press release Thursday. “As we have seen in states that already extend marriage to same-sex couples, this spending boost can lead to an influx of tourism dollars that benefit local businesses and an increase in state and local tax revenue.”

Many states have yet to open marriage to all couples. The Williams Institute study reveals that states in the South “that have been slow” to open marriage to same-sex couples could still see “a total economic benefit of $733 million.”

Williams Institute

The report also shows that 29 percent, or $750 million nationwide, “remains unlocked by states that have not yet extended marriage to same-sex couples.” (Click here to view the interactive data.)

Williams said that the benefit to Hawaii, which legalized gay marriage in late 2013, was estimated to be $19.3 million in spending, $800,000 in tax revenue and 61 new jobs.

Last month, consumer finance site NerdWallet released a study that estimated gay weddings could have a $26.6 million benefit to Hawaii in additional annual revenue.