The answer is the cut in top rate of Income Tax from 50p to 45p. (apart from the initial VAT increase).
That should come as no surprise to readers of this site, but will be a shock to many of the conventional pundits who have taken the precaution of not reading the latest HM Revenue and Customs figures which get in the way of their usual prejudice on the topic.
I do not understand where the Treasury got their £100 m cost of the 45p rate from. The Revenue and Customs figures for what actually happened is stunning proof that the tax cut from 50p to 45 has led to a big tax increase on the rich. Total income tax collected from people earning more than £150,000 has surged from £40bn to £49bn this year compared to last. It has more than made up for the loss of tax revenue from lower earners following the big increase in tax thresholds.
The 50p rate was costly. The UK lost high earners overseas, and encountered the ability of rich people to earn less and declare less income when rates are high. The rareified group of people earning more than £2m declared income of £12.2bn in 2012-13, but paid tax on £26 bn of income the following year with the lower rate. This small group of people alone more than paid for the rise in threshold to take many lower earners out of tax altogether.
The top 1% of earners now earn 13% of the income but pay 28% of the total income tax. The top 5% earn one quarter of the income but pay around half the total income tax. This progressive structure works as long as the government does not get too greedy, setting a higher rate which means the rich pay less because they either go or they earn and declare less.
The tax revenues generally are not as buoyant as the Treasury and OBR have been forecasting.Income tax, which brought in £152bn in 2011, fell in 2012, and only recovered to £158bn in 2013. This is despite a £9 bn tax hike on the high earners, showing the state is still collecting less from most taxpayers.
I wonder how much more revenue the Treasury would enjoy if the top rate were set at a more competitive rate? I suspect that too would see a further surge in revenue, money the state clearly needs to end the deficit. The very small group of people earning more than £2m a year will pay £10bn of income tax this year, exactly double the previous year.
(These figures are taken from HM Revenue and Customs Tax Liabilities Feb 2014 edition)