Brown still hovers over the 50p tax debate

A number of papers report today that George Osborne is minded to replace the 50p tax with Gordon Brown’s original proposal: a 45p tax. How the ex-PM will be laughing. As he knows, even the 45p tax will lose money — that’s why Labour didn’t raise the top rate until the final four weeks of its 13 years. But the Tories haven’t worked that out yet, and the Treasury is still working on the false assumptions he programmed into it.

In short, the amount of money that either tax rate will raise depends on what’s called the “taxable income elasticity,” or TIE — a figure suggesting how responsive various taxpayers are to rate changes. It varies for income groups. The lower-paid are less able to move their labour or money around than the rich. As various countries across the world realised this, they worked out that the best way to squeeze the rich was by lowering their tax rate.