Stamp duty is a really lousy tax. It’s bad enough when applied to property purchases, where it suppresses economic activity and restricts labour mobility. The version that imposes a 0.5% tax on share purchases may be even worse, according to some economists. It depresses trading and lowers share prices, so raising companies’ cost of capital and reducing investment.

In an ideal world, stamp duty would be scrapped. In the real world, that is not going to happen. Stamp duty on shares would have been judged a politically ideal tax by Jean-Baptiste Colbert, Louis XIV's finance minister. It plucks plenty of feathers from the goose with minimal hissing.