Jonathan Anomaly asks, “Is global wealth inequality unjust?” Anomaly and Dan Moller suggest that global wealth inequality may be less unjust than a lot of people think because rich countries have good political institutions and cultures that encourage social and scientific experimentation, not because they are actively harming poor countries.

Moller’s argument is that if wealthy countries did not cause global poverty they have no duty to provide aid. His main targets seem to be Richard Miller and Thomas Pogge, who argue that the system of global trade, which is imposed on everyone in the world, does cause poverty in poor countries. I agree with Moller that if anything, the system of global trade has made everyone better off, though it has made some much better off than others. And like Moller, I don’t think inequality is necessarily a moral problem. But like Pogge and Miller, I do think it is a moral problem if a system of property is imposed on everyone and it leaves some people so desperately poor they don’t have enough.

This argument is the same as my argument for the basic income. As Harry Frankfurt writes in one of my favorite papers, we should care about everyone having enough rather than an equal share. It is much easier to calculate an equal share than to calculate what counts as enough, but enough is what matters. Though it requires a further moral argument to say what enough is, I think most of us could agree that conditions extreme poverty do not give a person enough, whatever enough means. More than a billion people live in extreme poverty, and their lives are governed by a global property system that they have no choice but to participate in. My intuition is that just as domestic property systems should provide citizens with a basic income, a similar argument can be deployed to support limited duties of assistance for people in extreme poverty if we could know that assistance could make a meaningful difference.

I imagine a lot of BHL readers will be pretty unsympathetic to this argument. Some libertarians will object to my claim that property systems are coercive in ways that require providing everyone who is coerced by a property system to have enough. Some libertarians seem to think that the existing system of global capitalism is just everyone exercising their natural pre-political property rights without violating anyone else’s entitlements. Or, some people think that assistance would just do more harm than good, and people aren’t owed assistance if it would make the global rich worse off without making anyone better off. Of course it’s hard to know what would be enough assistance. Aid may not work. If aid works, it’s hard to know why. It’s hard to know how to make aid better too. But there are amazing researchers who are working to find the answers to these questions. Some worry that aid is paternalistic or infantilizing, but it doesn’t have to be. Just because we don’t know how best to improve the lives the global poor doesn’t mean we should stick to the current system of basically not trying at all.

For libertarians who are skeptical of wealth redistribution though, here is another reason that global wealth inequality is unjust—borders. As my co-blogger Chris writes, there’s no such thing as a closed border libertarian. As far as I know, Pogge doesn’t mention the global system of borders in his argument for eradicating systemic poverty and Moller doesn’t discuss immigration in his article either. This is a striking oversight. Both Moller and Anomaly emphasize the non-zero sum nature of trade. Moller considers and responds to the objection that the rich got rich by unfair trade practices, but does not include borders on the list of unfair trade practices.

I’m not saying that rich countries got rich by turning poor people away at the border. I suspect the opposite is true, and that rich countries got rich when they had a lot of migration (like the US in the 19^th century) and continue to get rich despite immigration restrictions. But one thing is clear, poorer people are poorer because of the border system. As Jason Brennan points out, opening the borders would not only respect people’s freedom of movement and association, it would also add trillions to the world economy and benefit rich and poor countries alike.

So yes, global wealth inequality is unjust. Not because rich countries cause poor countries to be poor, but because coercive property rules and borders trap people in conditions of extreme poverty. For these reasons, even libertarians should support policy reforms that improve the lives of the global poor—especially open borders.