Today’s parliamentary debate on population is really about immigration. This is both because net migration is a significant driver of UK population increases, and because reduced immigration is the key demand of the e-petition which sparked the debate, and of those proposing the motion. It is not clear whether those who are promoting the "no to 70m" proposition are themselves really driven by a concern about population increases and their effects; or whether they are really more concerned about immigration (or about particular kinds of immigration). It certainly seems unlikely that they would be in favour of more immigration if British emigration suddenly increased, or the British birth rate suddenly dropped.
In effect, this is a debate about the government’s net migration target, which itself only really makes sense if the driving concern is population. The most recent estimates suggest that net migration is running at well over 200,000 a year. The government’s target is to reduce that to less than 100,000 a year. Those who support the "no to 70m" proposition are calling for net migration of less than 40,000 a year (and, in many cases, for net migration of zero).
Leaving aside the fact that the existing net migration target is looking impossible to meet, that in the current context, net migration could only be cut to the levels demanded by the "no to 70m" camp at huge economic cost, and that those supporting the motion have no clear account of the policies that would be required to cut net migration so drastically, it is worth considering the population and net migration debate on its own merits.
The argument that any particular population level is a problem per se is clearly incoherent (why 70 million? Why not 80 million, or 40 million (as called for by Population Matters)?). The more sensible debate is about population increase (pace of change) and distribution, and the attendant issues. Those issues are real ones – housing, congestion, the allocation of funds to public services. But none are well served by a policy driven entirely by a net migration (or population) target, for at least two reasons.
The first is that a focus on overall net migration (or total population) can hide all sorts of different trends with different impacts and effects. For example, if immigration of ten million a year was matched by emigration of ten million a year then net migration would be zero, but the effects of the resulting population "churn" would almost certainly be negative. Similarly, if the emigration of one million high-skilled workers was matched by the immigration of one million low-skilled workers, then the UK might well be worse off as a result.
The second is that most of the impacts of population growth are local or regional, rather than national. A national net migration target does nothing to address local or regional population pressures. If London received net international migration of one million and Scotland received net international emigration of one million in the same year, then net migration would be zero but the consequences for both London and Scotland would likely be negative.
We should have a political and policy debate about population. It should be a debate about the rate of population growth and the distribution of population in the UK. It should be a debate about housing, and transport, and energy, and water, and public services, and how we manage an ageing population, and any number of other things. It should not be a debate about whether the UK population should be 70 million (or 60 million, or 40 million).
We should also have a political and policy debate about immigration. It should be a debate about the pace and nature of migration flows to and from the UK. It should be about jobs and wages, and economic growth, and public services, and culture, and community, and a whole range of other issues. It should not be a debate about whether net migration to the UK should be 100,000 a year (or 40,000, or zero).
None of this is to deny the connection between migration and population, of course, but when the population debate becomes all about immigration, and the immigration debate becomes all about population, then both are limited and unproductive.
Sarah Mulley is Associate Director for Migration, Trade and Development at IPPR