If Gordon Brown had reached a different judgment on his famous “five tests”, what might have been the economic consequences?

Critics say my estimate – that the British economy is around 5 per cent smaller due to Brexit – is implausibly large. This insight tests their scepticism against other ways to estimate the cost of Brexit.

Now that many advanced economies have recovered and are close to – or above – their pre-pandemic level of output, we can compare Britain’s economic performance to its peers. The results are troubling.

Kira Gartzou-Katsouyanni, Max Kiefel, and José Javier Olivas Osuna write that the Leave vote can be attributed partly to political discontent associated with trajectories of relative economic decline and deindustrialization.

In September 2021, UK goods trade was 11.2 per cent, or £8.5 billion, lower than it would have been if the UK had stayed in the EU’s single market and customs union.

Now that Brexit has been ‘done’, the British government is refusing to talk about it. But the rapidly escalating crisis in the UK has everything to do with the country’s departure from the EU. The opposition, meanwhile, has gone awol.

It's been five years since the UK voted to leave the EU. The vote appalled those who saw it as economic self-sabotage. But those in favor of leaving were not swayed by economic arguments — and likely still aren't today.

So far, in the first two months of Brexit, the following industries have indicated that they have been harmed: Aerospace; Airlines; Architecture; Art and Antiques; Beer; Bees; Cattle and horse breeding; Charities; Cheese; Chemicals; Cars; Classic Cars; Construction; Cosmetics and Perfume; e-Commerce; Fabrics; Fashion; Ferry services; Film and TV production; Financial Services; ...

There is an obvious flaw in advocating Brexit on the basis that it’s less costly than the worst pandemic the world has faced in a hundred years. But this aside, the claim Covid-19 is a bigger economic shock than Brexit deserves further interrogation.

A 19th Century trade agenda will decimate the most productive parts of the 21st Century economy.

The biggest crisis of Brexit to date actually still lies ahead of us in late 2020.

Dr Thomas Sampson is a Lecturer in the Department of Economics and a Trade Research Programme Associate at the LSE’s Centre for Economic Performance.

Their forecast of income gains from Brexit contrasts with all other economic analysis, write Thomas Sampson, Swati Dhingra, Gianmarco Ottaviano and John Van Reenen.