If wages rise, productivity doesn’t, prices do, unemployment does too and interest rates go up, the economy will experience downturn and perhaps recession.  At which point immigration will presumably fall, as it did in the wake of the financial crash – or else perhaps not rise much from its present condition.

Which in the year to March 2021 saw an 87 per cent fall in arrivals and a 78 per cent reduction in visas (including a 37 per cent reduction in work visas).  That’s the effect of Covid and lockdowns for you.

So what will happen if wages rise, productivity does too, prices don’t (or at least not as fast as they would have done otherwise), unemployment falls and interest rates stay stable?  Boris Johnson is suggesting that in these circumstances immigration won’t rise much, either: that’s the thrust of his argument about lower migration, a levelled up economy and higher wages.

Such an outcome is unlikely.  Certainly, net migration to the UK from the EU fell between 2016 and 2019 to 49,000 – close to the lowest level since 2003.  The Prime Minister is holding his line on HGV drivers by issuing only 5000 visas, largely for European lorry drivers, while Keir Starmer wants 100,000 issued.

However, net non-EU immigration rose between 2013 and 2019, reaching 282,000 by the end of that year – the highest level ever recorded.  The year to March 2020 showed an overall net migration figure of 313,000.

The Government has, of course, abandoned a net target altogether, going instead for its beloved “Australian-style points-based system“.  There is now no annual limit on semi-skilled work permits;  qualification requirements and the salary threshold has been lowered; an unlimited number of foreign students can stay on for up to two years; the obligation to first advertise jobs in the UK has been dropped.

All in all, the open secret of government migration policy is that it is relatively liberal, at least compared with what came before.  There is merit in the broad, strategic nature of the change. The net target made little sense – since, after all, government can’t control outflow.  And the Australian-style branding, as Dominic Cummings grasped, appeals to voters.

Sunder Katwala has argued on this site that “a long-term softening of public attitudes has continued during the pandemic”.  Forty-six 46 per cent of the public seeing migration as positive and 28 per cent negative, he reported, “a direct reversal of the position in 2015-16”.

The mere fact of “taking back control”, and the impact of Brexit on EU migration, is likely to have affected attitudes.  And it stands to reason that the growth of Britain’s ethnic minorities should impact on attitudues to immigration – at least in terms of race.  However, evidence suggests that concern about the issue rises when numbers increase.

According to YouGov, immigration / asylum is now third equal with the environment among voters’ concerns, with 55 per cent of Conservative voters naming it, “a startling rise of 24 points since the start of the year”, according to MigrationWatch.  Your guess about why this has happened is as good as ours (which, for the record, is: channel boats).

Maybe attitudes to immigration will stay relatively relaxed, even if Hong Kongers turn up in larger numbers than anticipated.  But whether they do or not, and despite the obscurity of the figures, the pre-Covid evidence suggests that, bar a downtown, net migration will grow.

If this is so, we don’t see where the Prime Minister gets his suggestion of lower immigration from.  Yes, it will be lower than it would be under Labour.  And, yes, EU migration looks set to remain relatively low by recent standards.  But overall, net immigration seems to us more likely to rise than not.  Which is one more reason to be sceptical of the case that Johnson is putting.