The Office for Budget Responsibility forecasts covered the taxes due to be devolved to the Scottish Parliament from April 2015 following the Scotland Act.
It said the fact Scotland has proportionately fewer higher-rate tax payers than the UK as a whole combined with raising the personal allowance to £10,500 from 2015/16 would lower the Scottish share of tax receipts.
The OBR statement said: “Scottish businesses trade more with the rest of the UK than with the rest of the world combined.
“The separation of tax, regulation and welfare systems, and the emergence of a border effect would make it harder for goods, capital and workers to move between Scotland and the continuing UK.”
