Bottom of barrel

Sam McComb (Letters, 8 July) is adamant that rUK would do a deal on a currency union ­because the oil revenues are critical to its economy. Holyrood’s hoped-for figure for oil revenues was £10 billion in its 2013 Scotland’s Balance Sheet estimates, but the actual value was well down on that: forecast by experts to stay in the £3bn-4bn per annum range, possibly even lower.

The £12bn-24bn always quoted as still waiting to be pumped up could give a further two or three decades of fair yield, but at ever-increasing cost per barrel, so there can be no expectations of additional revenues.

The UK economy is thus not critically dependent on the oil receipts, although the whole oil/gas endeavour contributes a moderate percentage to GDP. There seems no need for rUK to have to take on the risky role of lender of last resort for Scotland in a formal currency union just to keep oil monies coming in.

For both Scotland and rUK, oil revenues will be slight after another 40 years, so permanent separation means they must be replaced from other sources – Holyrood has yet to spell out how.

Joe Darby

Dingwall

Ross-shire