Humza Yousaf might have hoped for a better week. On Wednesday, the First Minister gave a speech at the European Institute of the London School of Economics, setting out why Scotland’s economic future would be brighter if it was an independent country. Some in the room were enthusiastic, but the Scotsman quietly drew attention to an LSE study from 2021 which had found that ‘the economic costs of independence are two to three times greater than the impact of Brexit’.