WHAT IS THE APPROPRIATE "TFR" IMMIGRATION RATE FOR THE U.K.?

Paddington Bear working as a Deliveroo Driver on a "Skilled Worker" VISA

by Duns Scotus

There is a lot of fevered, heated, and polarised debate over the question of immigration. Driven by sheer emotion, partisans on either side constantly argue from totally ludicrous and irreconcilable positions. This makes every thing rather meaningless and, worse than that, tedious and sterile.

Pro-immigration activists are all about the boost to the economy, GDP, and how we need foreign workers to do the jobs "lazy" Brits don't want to do. In short they make ridiculous "economics only" arguments. Meanwhile anti-immigrant activists often lean towards unrealistic demographic pictures of sealed borders and pristine racial purity. 

So, is there such a thing as a sensible Aristotelian path somewhere down the middle between the frankly moronic and soulless economic argument and the sadly unrealistic and delusional restrictionist argument?

The best that can we can do is to create a sensible middle point, with which most sane people across the spectrum could partially agree with. I propose that this would be to base immigration on the total fertility rate (TFR), commonly expressed as the number of children per woman.

This won't keep everyone happy but it at least gives us a rough, workable idea of where (given certain assumptions about the kind of society we have) where immigration should be. Of course, those assumptions -- such as prioritising GDP, maintaining population at present levels, filling certain labour shortages, and attitudes to family formation -- should also be open to question. 

So, basing things on TFR and the assumptions of a relatively "steady state" society and economy, what is the appropriate immigration rate for the UK?

This is not a difficult calculation to make. The UK population in 2023 was estimated at 68.3 million, which is around 13 million women of childbearing age (approximately 30 years, ages 15–44). 

Meanwhile the UK total fertility rate was 1.44 children per woman in 2023. As you need a replacement level of 2.075 for a stable population without immigration, you can see it is well short of what it should be, and also that this creates an aging and shrinking society, which makes it extremely hard to maintain the status quo. 

But exactly how much is the shortfall?

With around 13 million women of childbearing age, each woman needs to have 0.635 more children over her reproductive lifespan, so we can easily estimate the number of additional births need: 

• Annual births per woman at TFR 2.075: 2.075 ÷ 30 ≈ 0.0692 children per woman per year.
• Annual births per woman at TFR 1.44: 1.44 ÷ 30 ≈ 0.048 children per woman per year.
• Shortfall in births per woman per year: 0.0692 - 0.048 = 0.0212.
• Total shortfall in births: 0.0212 × 13 million ≈ 275,600 fewer births per year compared to replacement level.

This means that the appropriate immigration rate given the UK's TFR is 275,600 people annually.

Meanwhile, for the years mentioned in our calculation, the UK imported approximately 1.218 million people, according to provisional estimates from the Office for National Statistics (ONS). This is what is now being called the "Boriswave" after the Prime Minister whose policies led to it.

Once a "TFR immigration rate" of 275,600 people per year is widely accepted as a political consensus, it will then be possible to move on to other aspects of the debate, like the question of the costs and the benefits of boosting TFR and the nature and quality of immigrants. Here it could be argued that immigrants should be either highly skilled or from countries that are racially and culturally akin to Britain's core population.