The Sage of Ely tells us that:
Labour markedly and appropriately challenge this. In practice the IFS doubt they can deliver but I in turn doubt some of the IFS assumptions: if they think there is a Laffer curve effect in the tax rate range that Labour is proposing then they’re wrong.
An income tax rate of 67, 68% won’t have any Laffer effects? Spudda will no doubt tell us about the Diamond and Saez paper. Then mutter something about 76% and so on. But that’s for a system without allowances. 54% is the peak with allowances – and yes, a residence based taxation system is an allowance in this meaning of the word.