The last few years have been salutary for those who discount unlikely outcomes, such as brexit, donald trump, and the return of gareth bale to tottenham hotspur. clearly the improbable does happen, and our failure to anticipate it only makes it more shocking.but there is a countervailing phenomenon that can warp our perspective: discounting the most likely outcome.

It was evident this week, when a cohort of british conservative mps decided to antagonise us presidential candidate joe biden for pointedly restating his commitment to the good friday agreement. im not sure why iain duncan smith and conor burns overlooked the probability that mr biden will be the most powerful man in the world in four months, overseeing the trade deal that they so badly want. unless of course they think their interventions will swing voters in north carolina.

A reluctance to anticipate the most likely outcome is also evident with regards to the brexit talks. for the past fortnight, westminster has been consumed by the prospect of the uk leaving the eu without a deal. prime minister boris johnson has sought to strengthen his negotiating hand by pushing a bill that would break international law, while also failing to address the unlikely scenario that he claims to be worried about, an eu food blockade of northern ireland.

It is right to criticise the governments actions, and right to prepare for the possibility of a no-deal brexit. but let us not lose perspective. bilateral talks this week went well; the eu has not risen to the uks provocation. london and brussels reached a deal last year, despite a game of cross-channel chicken. they will probably reach one this year too, not least because mr johnson cannot afford to feed scottish separatism.

The most likely result is that a breakthrough will occur, and the lawbreaking clauses of the uks internal market bill will be dropped. those who acted honourably, like the government's law officer for scotland, richard keen, who resigned this week, will look irrelevant.

If we dont prepare for this, we will be too shocked to process its most salient feature namely, that the brexit deal itself will almost certainly be a very bad one. it will mean no tariffs and quotas on goods, but it will not remove the need for regulatory checks. it will do little to ease the sale of services to the eu. it will lead to a sharp increase in customs bureaucracy and duplicate product approvals.

The last official estimates were that the british economy would be 5-7 per cent smaller in 15 years under such a canada-style arrangement than it would have been as an eu member. brexit could plausibly hit the economy more than coronavirus.

This is a harder brexit than most supporters voted for in 2016, and a harder brexit than many people can make sense of now. after so many threats of catastrophe over the past four years, businesses have boy who cried wolf syndrome, says sam lowe, of the centre for european reform think-tank. but the bumps are coming.

Mr johnsons premiership will soon be further in deficit. his first significant legacy will be to have broken parts of the british economy and the civil service with a vague promise to glue them back together again even better.

Already conservatives are losing faith in his handiwork. the average frat-boy manages his party more carefully than mr johnson does. i lose track of which mps and grandees are rebelling on which issues. the common theme is that they have no deference to the prime ministers judgment. if he sides with them, they use him for his powers of advocacy, but if he sides against them, they resolve to twist his arm later.

Who can blame them? mr johnsons views on every issue, from wealth taxes to environmental regulation, appear up for grabs. his answers at prime ministers questions are often embarrassing. if he knows so little detail at the meeting for which he presumably does most preparation, his mps can only assume he is even worse in all the others.

The left of the party is disappointed, but not entirely surprised, says one tory mp. the right is coming to the view hes incompetent. are there really plans torevive the economy, to balance uk agriculture with a us trade deal, and to fix the care system?

The end of the transition period will be the first of many moments when mr johnson will no longer be able to have his cake and eat it. in the most likely scenario, his real sin will not be to have pushed britain over a trading cliff edge. it will be to have led us down a path where the alternative a canada-style deal is not that much better.

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