Economists are a notoriously self-interested bunch. But a British outfit called Pro Bono Economics is giving away its services. The group’s leader is Martin Brookes, a British economist at a hedge fund, who got the idea after a phone call.

“A big U.K. charity called Barnardo’s, which is a children’s charity, rang me up and said could they borrow an economist from me,” Brookes says. “Because they didn’t know where to find them and they couldn’t afford to hire one even if they did know where to find them.”

It struck Brookes that if a large, established charity was soliciting economists, others might well be in need. So along with a few friends he started Pro Bono Economics, a nonprofit that matches U.K. charities with economists willing to donate their time.

“For us,” Brookes says, “the pitch of Pro Bono Economics is that economists are better with a spreadsheet than they are with a paintbrush. And you should marry them up, those economists up with a spreadsheet rather than give them a paintbrush to paint a hut.”

So far, the experiment is showing promise. Pro Bono Economics has brought economic analysis to projects that have not had the advantage of such scrutiny — although not all the scrutiny turns out to be positive.

“We’ve worked with a number of charities where the evidence has not been conclusive that they are having a big impact,” says Sue Holloway, the group’s director, “or it’s shown that, at the moment, they’re not making much change in the way they were expecting.”