Population Projections

Almost all of the work the CSO does is retrospective – collect data on what has already happened.  There is one area where part of the work undertaken is forward looking – demographics.

After every Census the CSO use a set of fertility, mortality and migration scenarios to project out the country’s population by several decades.  These are not forecasts; merely projections of what might happen under different scenarios.  The most set available are those undertaken following Census 2016 and they give projections out to 2051.

The projections were based on three scenarios of net inward migration:

• M1: net inward migration of 30,000 per annum
• M2: net inward migration of 20,000 per annum
• M3: net inward migration of 10,000 per annum

and two fertility scenarios:

• F1: fertility rate remains at 2016  level of 1.8
• F2: fertility rate declines from 1.8 to 1.6 by 2031 and stable thereafter

When combined, the scenarios give six projections with the two fertility scenarios used for each of the three migration scenarios.

We have now passed the subsequent census and can compare the projections to the actual outturn of recent years.  Obviously, there are things the projections, which were published in June 2018, could not be expected to account for such as COVID-19 and the Russian invasion of Ukraine.

Anyway, here are the six projections and the actual outturns seen.

Reality was outstripping the projections even before they were published.  Of course, this reality was not confirmed at the time and only fully revealed with the results of Census 2022.  The latest population figure for 2018 (4.885 million) is 20,000 more than the highest projection for that year (M1F1 4.865 million).

For 2020, (with the figures covering April of each year) the gap between the actual population (5.029 million) and the highest projection (4.988 million) was 42,000.  The gap to the lowest projection for 2020 (M3F2 4.904 million) was 126,000. And that is for a time before COVID or Ukraine could have any impact.

For 2023, just five years after the projections were published and the gaps now range from 117,000 to 274,000.  Now clearly, the impact of those fleeing the war has impacted that but there were already significant, and growing gaps, by 2018.  Under the lowest projection (M3F2), the actual population of 2023 was not due to be reached until 2034.

We can compare the migration scenarios set out in the projections to what has actually happened since 2016.

• 2017: +39,200
• 2018: +44,400
• 2019: +44,000
• 2020: +44,700
• 2021: +21,800
• 2022: +51,700
• 2023: +77,600

Hindsight is 20/20 vision and all that, but right off the bat it can be seen that even the highest scenario of +30,000 per annum was significantly exceeded.  More recent years have been impacted by COVID19 and Ukraine.

Are such population projections important?  They are to the extent that they impact policy.  Our current National Planning Framework was published in 2018.  The baseline projection on which this was based was for the population to reach 5.7 million in 2040, just 400,000 more than the 2023 population. The NPF stresses the need for plans to be flexible and the ability to adapt for higher population outturns.  We are already there.

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