Professor John FitzGerald:

For the direct tax receipts there is an attribution, but I am not sure how good that is. Corporation tax is paid by a company to the Inland Revenue in the United Kingdom by the head office. If Tesco makes profits in Northern Ireland, those profits are aggregated in London and that tax is paid by Tesco headquarters. Therefore, there is an undercount of corporation tax in Northern Ireland.

I took the national accounts gross operating surplus for Northern Ireland and the gross operating surplus for the UK and attributed the corporation tax on that basis. I added in a few hundred million more in corporation tax. It is more complicated. There is another item, that is, refunds of VAT to Northern Ireland of £700 million or £800 million. It is in under a miscellaneous cost to the UK, but it is actually a refund of VAT. I think the VAT figures are reasonably good.