There was an extremely interesting blog posting on Wings over Scotland about the size of Scotland's exports.
This made me think about the consequences for the finances of an independent Scotland.
First of all, the figure provided by WoS is $20,886 per capita, but that's excluding oil. According to STV, Scotland's oil and gas exports are worth about £7.6bn, which is about half the amount produced. If we assume that half of this is actually exported to England, we get a rough figure of £11.4bn, which is $18bn. Per capita this is $3400, so a very rough estimate of an independent Scotland's exports including oil would be slightly more than $24,000 per person, which would make us number six in the World rankings, between Norway and Ireland.
There also tends to be some kind of correlation between exports and GDP. Looking for similar countries in this table, one finds Denmark and Sweden around 50%, Norway at around 40% and the UK at 30%. In other words, it would be really strange if Scotland's GDP was very low, and one would probably expect a GDP figure per capita between $50,000 and $60,000, which would definitely place Scotland in the World's top-10, way ahead of the UK (which has a GDP per capita of slightly less than $40,000).
My calculations are very rough, so it's hard to say exactly how rich an independent Scotland would be, but it looks likely it would be much richer than the UK, and potentially even richer than Norway.
My only remaining question is why previous calculations of how much better off Scotland would be after independence have been so cautious. It seems to me that we're likely to be talking about every single person in Scotland being better off to the tune of about £10,000 per year (between $10,000 and $20,000). Where has Westminster been hiding all that wealth?