Diasporas, Swamping, and Open Borders Abolitionism
By Bryan Caplan
The third big thing we know [about immigration] is that the costs of migration are greatly eased by the presence in the host country of a diaspora from the country of origin. The costs of migration fall as the size of the network of immigrants who are already settled increases. So the rate of migration is determined by the width of the [income] gap, the level of income in countries of origin, and the size of the diaspora. The relationship is not additive but multiplicative: a wide gap but a small diaspora, and a small gap with with a large diaspora, will both only generate a trickle of migration. Big flows depend upon a wide gap interacting with a large diaspora and an adequate level of income in countries of origin.
Diasporas scare Collier. Why? Because diasporas have the potential to snowball. In economic jargon, there “may be no equilibrium.”
For a given income gap, migration would only cease to accelerate if the diaspora stopped growing. Since migration is constantly adding to the diaspora, it will only cease to grow if there is some offsetting process reducing the size of the diaspora.
Since Collier is a nationalist at heart, the prospect of snowballing diasporas horrifies him. If everyone in Sudan moves to the U.S., it dilutes American identity – and eventually destroys Sudanese identity.
If you’re a pragmatic cosmopolitan, however, Collier’s diaspora story makes open borders abolitionism suddenly look reasonable. If immigration were based solely on income gaps, any country that opened its borders would be swiftly swamped by hundreds of millions of migrants. The cost of adhering strictly to the principle of free migration could be high for the native population. Maybe everything will be fine in the long run. But in the short run, there will be shantytowns, begging, poor sanitation, and much ugliness.
On Collier’s account, in contrast, flinging the borders wide open wouldn’t lead to a mass exodus. Instead, migration would start small, then gradually accelerate to very high levels. First a few adventurous Sudanese come. Then they write home, attracting a larger second wave. This in turn gives courage to a still larger third wave. Eventually, most of Sudan migrates; diasporas feed on themselves. But the process takes decades, giving U.S. business plenty of time to prepare for all the new customers and employees. In the end, the migrants’ remittances and repatriates turn their depopulated Old Country into a quaint tourist and retirement community like Puerto Rico.
Nationalists will rankle at this picture. Nations die in slow motion, and open borders abolitionists rejoice? But I fail to see the problem. “Nations dying” is merely a metaphor. People living – and dying – in wretched poverty is a harsh reality. Open borders saves the people and lets the metaphors fend for themselves.