A 50p top tax rate: more or less money for the government?

The UK Shadow Chancellor, Ed Balls, has announced that, if Labour is returned to power in the next election, it will bring back the 50% top rate of income tax (see also). This will apply to incomes over £150,000.

But will this raise more tax revenue? The question here concerns incentive effects. Will the higher rate of income tax discourage work by those earning £150,000 or encourage tax avoidance or tax evasion, so that the total tax take is reduced? The Conservatives say the answer is yes. The Labour party says no, claiming that there will still be an increase in tax revenue.

The possible effects are summed up in the Laffer curve (see The 50p income tax rate and the Laffer curve). As the previous post stated:

These arguments were put forward in the 1980s by Art Laffer, an adviser to President Reagan. His famous ‘Laffer curve’ (see Economics (8th edition) Box 10.3) illustrated that tax revenues are maximised at a particular tax rate. The idea behind the Laffer curve is very simple. At a tax rate of 0%, tax revenue will be zero – but so too at a rate of 100%, since no-one would work if they had to pay all their income in taxes. As the tax rate rises from 0%, so tax revenue would rise. And so too, as the tax rate falls from 100%, the tax rate would rise. It follows that there will be some tax rate between 0% and 100% that maximises tax revenue.

As Labour is claiming that re-introducing the 50% top rate of income tax will increase tax revenue, the implication is that the economy is to the left of the top of the Laffer curve: that, at current level of income, the curve is still rising.

Work by HMRC, and published in the document The Exchequer effect of the 50 per cent additional rate of income tax, suggested that the previous cut in the top rate from 50% to 45% would cut revenue by around £3.5 billion if there were no incentive effect, but with the extra work that would be generated, the cut would be a mere £100 million. This implies, other things being equal, that a rise in the rate from 45% to 50% would raise only a tiny bit of extra taxes.

However, the HMRC analysis has been criticised and especially its assumptions about the incentive effects on work. Then there is the question of whether a rise in the rate from 45% to 50% would have exactly the reverse effect of a cut from 50% to 45%. And then there is the question of how much HMRC could reduce tax evasion and avoidance.

The following article from the Institute for Fiscal Studies examines the effects. However, the authors conclude that:

… at the moment, the best evidence we have still suggests that raising the top rate of tax would raise little revenue and make, at best, a marginal contribution to reducing the budget deficit an incoming government would face after the next election.

But there is also the question of equity. Putting aside the question of how much revenue would be raised, is it fair to raise the top rate of tax for those on high incomes? Would it make an important contribution to reducing inequality? This normative question lies at the heart of the different views of the world between left and right and is not a question that can be answered by economic analysis.

Article

50p tax – strolling across the summit of the Laffer curve? Institute for Fiscal Studies, Paul Johnson and David Phillips (Jan 2014)

Questions