The three forces at play that raise serious questions about this year's census

·4-min read

The UK population may have fallen at the fastest rate since 1941 during the coronavirus pandemic, raising serious questions about the reliability of data collected in the census this year, economists have warned.

The census is the government's once-in-a-decade opportunity to survey all British households to understand the shape and nature of the population, yet this year it is coinciding not just with lockdown, but with three dynamics which are changing the shape of the population - perhaps permanently.

2020 is likely to go down as the first year in decades that more people died in the UK than were born. It is also the year that saw the fertility rate drop to the lowest level on record.

Finally, the year also saw an unprecedented outflow of migrants from the UK, especially London, during the coronavirus pandemic and its various lockdowns.

The upshot of the three forces is that the UK population may have fallen by as much as a million, according to economists. This fall would represent a 1.5% drop - the biggest since the 2.5% fall in 1941, itself largely a consequence of wartime mobilisation, as many troops left the country.

The census was cancelled in 1941 due to the war, but the Office for National Statistics has pushed on with the survey this year, even though many of the questions asked - not just about population numbers, but also about working patterns and transport use - will be skewed by lockdown.

Economist Jonathan Portes, of King's College London, whose research with fellow economist Michael O'Connor first identified the migration outflows, said: "It looks as if 2020 was the first year since World War Two that we saw a really significant population fall across the UK.

"It's ironic that this is just as we're coming up to the census. Because of the pandemic, there's lots of uncertainty about people's working patterns, about where they're living... and where we may have seen very large outflow of people going back to the countries where they first came from.

"We normally tend to think of demography and population as a very slow moving, often somewhat boring branch of statistics, but at the moment there is more uncertainty than there has been for a very long time, and that really matters to the future of the UK economy."

While some will argue that the UK was already overpopulated and that therefore a fall is long overdue, the drop may nonetheless have economic consequences.

Most studies have shown that immigrant workers tend to pay more in taxes than they receive in benefits, which implies that a smaller migrant population will mean resident Britons have to pay higher taxes in future.

Another consequence - though one most economists believe is a positive eventuality - is that property prices, especially rental prices in London, where most of the migrant population lived, have fallen sharply.

Many expect that these patterns will be reversed when lockdown is lifted, with a sharp influx of workers back to the UK to resume work. However, there are also deeper questions about the long-term dynamics in the UK population.

Up until recently, Britain's total fertility rate - the average number of children the average woman gives birth to - was among the highest in Europe. However, the rate has dropped in recent years and during COVID-19 it fell to 1.6. This is well below the 2.1 rate at which the population can sustain itself without inward migration, and the lowest level since comparable records began in the 1930s.

The root causes of this phenomenon are not fully understood, though some of the likely factors include higher house prices, which are forcing young couples to marry and settle down later than their parents' generation, as well as increasing cost and career pressures facing women.

According to campaign group Pregnant Then Screwed, 84% of parents said childcare costs were causing financial anxiety, with many prospective parents having fewer children than they might have planned.

Nonetheless, the upshot is that the fertility rate in the UK is now at the same level as it is in Russia, where the population has been shrinking for some years.

These statistics reflect complicated and intimate decisions being taken across the UK population - they are an incomplete depiction of the forces faced by those deciding whether to have children.

Yet the aggregate consequence is that even once one adjusts for the temporarily high rate of deaths due to COVID and the temporarily high rate of emigration of non-UK born workers, UK population growth may be considerably lower in the coming years than had previously been expected.