A state ban on gay marriage is costing the city of San Francisco millions of dollars a year in lost revenue and increased services, an economist testified Thursday in a lawsuit aimed at overturning the prohibition.

Chief city economist Edmund Egan said married people accumulate more wealth and have more to spend on property and consumer goods, which bolsters tax revenue.

He also said the city must spend more on health care for uninsured workers because same-sex couples are not always covered under their partner’s employee health care plans.

“It’s clear to me that Proposition 8 has a negative material impact on the city of San Francisco,” he said. “These are impacts that are hard to quantify, but over the long term they can be powerful.”

Egan testified during the fourth day of a federal trial on a lawsuit challenging Proposition 8, the ballot measure approved by statewide voters in 2008.

Read the rest of Lisa Leff’s AP article here.