Because Scotland benefits from higher spending and consistently generates lower onshore revenues per head, a large onshore deficit gap exists
The deficit gap is the difference between Scotland's deficit (in either per head or % GDP terms) and that of the UK overall.
The onshore (i.e. excluding North Sea revenues) deficit gap can be explained by the combination of higher public spending per head for Scotland and lower revenue per head.
We have focused on per head figures throughout these insights as we believe this is the easiest figure for the layman to relate to (and because the denominator doesn't change when switching between onshore and inc. North Sea revenue figures) - but the same analysis can be carried out on a percentage of GDP basis and a similar deficit gap picture results see [here]