It’s not a revolution then. Nor does it justify opposition claims that the wealthy will be leaving Scotland soon: people’s real behaviour is not nearly as sad or tax motivated as most right wing politicians think. Research in the USA proves that. But this is, none the less, deeply significant. There will now be a tax border between the rest of the UK and Scotland. There will be issues of Scottish residence to address, and dual residence to resolve. How employers run dual payrolls will have to be on the agenda: notice of coding will not forever address the differences in allowances, and cannot do so if rate changes do follow.
And the whole issue of how macro-economic stability for the pound is achieved when tax systems vary is now an issue requiring discussion because no one knows the long term answer to that, and we will need to do so.
Macroeconomic stability of the pound is affected by variances in tax rates? State income tax rates affect the stability of the dollar? Different levels of business rates in the old days affected the pound?