In my last post, I discussed the question of whether developed states should given replacement migration policies priority ahead of replacement fertility policies – or, in other words, whether they should give more importance to boosting the proportion of working-age persons in their populations by increasing their immigration rate instead of their birthrates. One relevant issue that needs to be tackled in assessing that question, which I touched on only briefly, is the impact of either policy on climate change. I said that replacement migration would likely have a more positive impact (or less negative impact) on climate change (essentially, it would have a smaller carbon footprint). In today’s post, I want to spell out that reasoning a bit more and tackle a related issue that I didn’t cover in my last post.
So, why should we think that replacement migration might have a lower carbon footprint than replacement fertility? The key reason is this. Both replacement migration and replacement fertility would introduce new people to the economy of a developed state and therefore increase its carbon footprint relative to introducing no new people. But unlike replacement fertility, replacement migration does this by removing a person from another state. This means that, while replacement fertility adds a whole life’s worth of carbon emissions, replacement migration shifts carbon emissions from one state to another, or more precisely, it shifts the carbon emissions that would have taken place during the adult portion of a life, from one state to another. If the immigrant in question moves from a lower emitting to a higher emitting state, the result would be a net increase in carbon emissions compared to no immigration. But the result is still lower carbon emissions compared to replacement fertility.
When thinking this through, it occurred to me that someone might object for climate-related reasons to both replacement fertility and replacement migration. Or, more precisely, someone might object for climate-related reasons both to replacement fertility and to the type of replacement migration that involves the movement of persons from lower emitting to higher emitting states. I’ve been giving some thought to how strong this climate-related objection is.
The first thing to notice is that the persons from whose point of view that climate-related objection can be raised are mainly people who are not yet alive and who will live in the future (the effects of carbon-emissions on climate change take quite a while to materialise). The objection thus runs into the “non-identity” problem. The problem arises for the objection because the identities of future people will depend on whether developed states adopt replacement fertility or replacement migration policies (or neither policy). A future person cannot reasonable say that she, rather than someone else, would still have been born, had developed states not chosen one of these policies but the other instead. This means that had a developed state not chosen whichever policy it did end up choosing but some other policy, that particular future person would not have existed and some other future person would have existed instead. And that means that whoever does end up coming into existence cannot say that she has been made worse off by the policy that was chosen compared to how "she" would have fared as a result of an alternative policy.
The non-identity problem is a serious problem for how we should think about climate-affected policies (and other policies). But responses to the problem have been proposed. I can’t go into them here. Instead, I will just assume that someone who raises the climate-related objection to both replacement fertility and replacement migration can avail herself of one of those responses and therefore stick to the objection that both of those policies give rise to reasonable complaints on the part of future people.
The key point I want to make is that we should not restrict our assessment of which population policy developed states should adopt in response to population ageing purely from the perspective of the interests of future people. People who live in the present matter too, and it may be the case that their interests would be harmed if developed states abstained from pursuing both a replacement migration or replacement fertility policy. If they did this, then, very roughly speaking, the result would be that presently alive people would have to work harder (if they are young) or make do with less assistance (if they are old). It’s not obvious that the complaints that either of those two presently alive groups of people would be weaker than the complaints future people would have if developed states abstained from both a replacement fertility and a replacement migration policy. So, the climate-related objection to both replacement fertility and replacement migration doesn’t obviously go through.