The Treasury have been too optimistic about how much extra revenue they will get from a big hike in the rate of Capital Gains Tax. Indeed, it is coming in this year £1.2bn down on last year’s forecast, or a whopping 23% shortfall. Just as they underestimate the extra revenue you get in from Income Tax rate cuts, so they exaggerate the extra revenue you get from tax rises.
In 2011-12 Capital Gains Tax brought in £4.3bn. This fell to £3.9bn in 2012-13 with the continuing higher rate, as I predicted but as many sought to deny. That was a fall of 10% in revenue. Not to be downhearted, the Treasury decided this was a one off event. They forecast a healthy rise in CGT this year to £5.1bn in the 2013 budget. A year later, in Budget 2014, the forecast for the year just about to end slumped from £5.1bn back to the previous year’s £3.9bn, still 10% lower than 2011-12.
The Treasury do not seem to understand CGT. People with assets have considerable scope to delay or cancel sales if the prospective tax bill is too high. Sometimes they can find offsetting losses to take if they do wish to sell something sitting on a profit. People with flats in London they do not use very much any more decide to keep hold of them as they do not want to pay all the CGT. People with shares sitting on good gains delay sales, and phase them when they have offsetting losses and allowances to cushion the tax bill. Assets which could be better used by others are not sold on.
The rate at which you would maximise CGT revenue is likely to be a low rate because it so easy for people with assets to avoid this tax quite legally. It is not tax avoidance to sit on an asset you no longer need because it stands on a big gain. Gordon Brown seemed to understand this, and took CGT down to 18% which may well be near the optimum rate to maximise the revenue. People wanting the public sector to spend more should worry that CGT is too high to maximise revenue at the moment. The Treasury needs to improve its model to forecast this tax more accurately.