document: Gerry Holtham was commissioned by the Welsh government to look at the pros and cons of the way that government gets its budget.
  He found, among other things, that Wales would be treated more generously if Wales were funded on the basis of need rather than the population-based Barnett formula.
  Politicians have used his findings ever since to make the case for a change to the formula on the basis of the shortfall suffered by the Welsh government.
  I've been talking to Gerry Holtham as part of a discussion on a report he wrote for the Institute of Welsh Affairs. So how big is that shortfall?
  He told me: "At the time we did the research it was Â£300 m to Â£400 m a year less than it would get if it were an English region getting needs-based grants. We don't know what that is now.
  "Given the squeeze on public finances it's probably a smaller number, the shortfall is probably less than it was then. Even then, it was only a couple of per cent of the Welsh budget so we're probably down to one per cent of the Welsh budget."
  In comments that may yet be worth recalling the next time you hear a politician use his figures, he added: "It's not going to change the world. Welsh government has to find a way forward apart from just complaining about the grant."
summary: He is Wales's most quoted economist, his name often called in aid by those who think the country is under-funded from Westminster.