In a previous post, I considered the considerable divergence, even among open borders advocates, about the raw count and selectivity of migrants under open borders. I argued that it is important to get more clarity on these questions, including understanding the source of disagreement and how different views regarding these can affect the other estimates (including economic growth estimates) related to open borders.
In this post, I attempt to sketch several arguments that could form building blocks of a case for open borders that is radically agnostic about how many people would move.
The right to migrate argument
This argument states, simply, that people have a right to migrate. Denial of this right is immoral. How many people would end up choosing to exercise that right is not of direct relevance. Migration restrictions are immoral because they prevent a large number of people who are in a position where they may wish to exercise the right from doing so. The human capabilities case for open borders is somewhat similar.
The lower bound argument
This argument states that even the lowest possible estimate of how many people would actually move under open borders (perhaps such estimates can be obtained by looking at the number of people who have moved under relatively modest migration liberalization regimes) is high enough to make open borders worthwhile. Whether we are talking of 10 million people over a decade or 200 million people over 2-3 years, open borders would have huge impact.
The “it anyway won’t happen immediately” argument
This argument views open borders as a goal we should set our sights on as we gradually work towards it. Thus, determining the numbers of people who’d migrate under complete open borders is at best an illuminative theoretical exercise and at worst a distraction from the more important goal of seeking marginal change that is far better understood. Some proponents of this argument many view open borders advocacy as a means for shifting the Overton window in a manner that makes immigration liberalization appear to be a more “moderate” position.
The “market forces will prevent swamping” argument
One of the concerns that critics of open borders have is that under open borders, countries (mostly rich countries) that are attractive targets for immigrants will get swamped with large numbers of migrants. This is part of the motivation behind the desire to estimate how many would move under open borders. Some open borders advocates believe that market forces, loosely defined, will take care of this concern. If too many immigrants are moving into the area, rents and other prices will rise and wages will fall to the level that it is no longer attractive to move to the destination. Other non-pecuniary negative feedback loops may also counter the swamping threat. Many people use phrases like “migration flows tend to be self-regulating” to describe this perceived phenomenon.
The “however much it takes to attain labor market convergence” argument
This argument states that migration will continue until there is (upward) labor market convergence between the sending and receiving countries. Convergence may not be complete, but may stop when the place premium between the two countries is a factor of 1.5 or less (i.e., there is only a ~50% wage gain from migrating). The point here is that we don’t know for sure how many people would need to move in order for this convergence to occur, because of countervailing factors: governments may begin instituting economic reforms once people start leaving en masse, emigrants may return to the country to set up new factories and business connected with other countries, etc. Or, this may not happen. Uncertainty about how things play out result in considerable agnosticism about the number of people who move, but relatively more certainty about the nature and desirability of the eventual outcome for humanity.