Population – how big is too big?

The increasing size of the UK population has become a major theme in the debate on immigration in the UK recently.

Reports often cite concerns that the UK population is heading toward 70 million, and argue that this is too high, unsustainable, or not in the national interest (Daily Telegraph 6 January 2010, Daily Mail 30 June 2011, Daily Mail 25 June  2011).

The UK population increased by just over 470,000 in 2009-2010, of which 226,900 was attributable to net migration with the rest attributable to ‘natural change’, though higher levels of fertility among migrants means that migration also has a positive impact on natural change. This is part of a long term increasing trend and projections suggest that the population will hit 70 million at some point around 2033.

>>Read our briefing on The Impact of Migration on UK Population Growth

But despite the regularly voiced concerns, most politicians have skirted the somewhat toxic issue of what size the population of the UK should actually be (BBC 4 July 2006).

In the past, the UK was explicit in not having a policy on population. In 2000, the official policy of the UK was restated as: “The United Kingdom government does not pursue a population policy in the sense of actively trying to influence the overall size of the population, its age-structure, or the components of change except in the field of immigration. Nor has it expressed a view about the size of population, or the age-structure, that would be desirable for the United Kingdom”

>>Read our policy primer on Demographic Objectives in Migration Policy-making

And there is still no agreement on whether there should be a “maximum population size” in the UK, and surprisingly little evidence to support assertions about how many people the country can support.

But the slew of references currently being made by those in the highest levels of politics to a population of 70 million being too large (Daily Mail 11 January 2010) suggest that the government now has some sort of limit in mind. In reality, though, no major political parties advocate a specific maximum population size.

Considering these issues, some key questions need to be answered: Is there a maximum viable size for the UK population? What factors should we base this number on? Can the government actually control population size – and if so, how?

But assessing what the optimum population of a country should be is exceedingly difficult – some would argue impossible. One idea, of course, is that that the nation’s population should be limited to a size that can be sustained by the resources available within its borders. This is also challenging to calculate with any precision – one of the few organisations that does, think-tank Population Matters (formerly the Optimum Population Trust), argues that to be sustainable the UK population should stand at around 20 million.

But many consider this to be extreme, and even Population Matters accepts that this number is so far away from the current level – a population of some 62,262,000 – that it would take centuries of focussed population management (they call for a reduction in the population of 0.25 per cent per year) to achieve it.

But there are also questions about what the impact of different approaches to managing population might be.

Allowing the population to continue to increase rapidly will raise concerns about pressures this will place on public services, the environment and other areas of life in the UK.

Limiting or reversing population growth may also have profound economic and social impacts – a falling population is associated with falling demand for goods and services and a smaller economy, for example.

What this leads us to is the conclusion that, in fact, there is no easy answer to the question of how large the UK population should be, or why.

However, the British public might reasonably believe that there is a target population size by oft-repeated rhetoric around the need to keep the population below 70 million – which serves little purpose other than to create confusion.