The Scottish National Party is calling for a second referendum on independence from the UK. This column examines the likely effect of changes in trade costs resulting from independence and Brexit on the Scottish economy, finding that independence would be two to three times more costly for Scotland than Brexit. In addition, rejoining the European Union following independence would do little or nothing to mitigate these costs, reflecting the fact that Scotland’s trade with the rest of the UK is around four times greater than its trade with the EU. The combination of Brexit and independence is estimated to reduce Scotland’s income per capita by between 6.3% and 8.7%.