See also: Ethics and philosophy, moral counter-case, open borders normative ethics summary.

A number of different normative ethical frameworks have been used to argue for open borders. While the arguments are somewhat distinct, it is not completely surprising that they all point in a similar direction. Philosopher Joseph Carens authored a 1987 article “Aliens and Citizens: The Case for Open Borders,” which, in the words of one reviewer, “made the idea [of open borders] intellectually respectable” by observing that multiple political philosophies support open borders. The abstract of Carens’s article runs:

Many poor and oppressed people wish to leave their countries of origin in the third world to come to affluent Western societies. This essay argues that there is little justification for keeping them out. The essay draws on three contemporary approaches to political theory — the Rawlsian, the Nozickean, and the utilitarian — to construct arguments for open borders. The fact that all three theories converge upon the same results on this issue, despite their significant disagreements on others, strengthens the case for open borders and reveals its roots in our deep commitment to respect all human beings as free and equal moral persons.

An interesting slogan form of the moral case was provided by economist Bryan Caplan in the title of a blog post, which lent this website its tagline: The Efficient, Egalitarian, Libertarian, Utilitarian Way to Double World GDP. (For more pithy formulations of the moral case, see our quotable quotes page.)

The libertarian case: individualistic, deontological morality

Libertarianism is a moral and political philosophy that gives considerable importance to individual freedom. The libertarian case for open borders has three basic components:

• The existence of a (presumptive) right to migrate, which stems from the broad libertarian belief that people should have the liberty to do whatever they please as long as it does not infringe on the rights of others.
• A limited conception of obligations to strangers that stresses, on the one hand, that we do not have strong positive obligations to care for the welfare of strangers, but on the other hand, also says that we have an obligation of not coercively interfering with others’ life choices.
• Self-ownership versus state ownership: People are their own masters, rather than the property of the governments of their country of citizenship. This libertarian argument is often used to argue for the right to emigrate, but can also be used to argue for the right to invite, and push back against collective property rights.

The pure deontological libertarian case would argue for open borders, even if the consequences were not great. A presumptive libertarian approach, that argues in favor of libertarian policies unless the consequences are terrible, would also support open borders assuming that open borders are not catastrophic. The presumptive libertarian approach is similar to some of the other approaches, such as the human capabilities and utilitarian approaches, that are discussed.

Even though most people are not libertarians, libertarian ideas do influence many people’s conception of morality. Moreover, the libertarian case is one that is easiest for people to relate to and evaluate without diving deep into the empirics of open borders, and therefore forms a good starting point for thinking about the ethics of open borders.

Good for the world: the utilitarian case for open borders

The utilitarian/consequentialist case for open borders relies broadly on two observations:

• The basic efficiency-based case for open borders stresses the huge gains to global production. A literature review by Clemens cites estimates of increases in global production of the order of 50-150%, captured by the catchy phrase “double world GDP”. There is considerable uncertainty surrounding the estimates, but even much smaller efficiency gains are very significant.
• Some of the poorest people in the world would see huge gains from open borders, accelerating the end of world poverty.

The main strength of efficiency and utility-based arguments is that, grounded as they are in quantitative estimation, they help us get a better idea of the magnitude of the issue.

Egalitarianism: equality of opportunity and equality of result

The egalitarian case has a number of different angles to it:

• More equal opportunity around the world. The claim is not that open borders would lead to perfectly equal opportunity, or even that perfectly equal opportunity is desirable, but rather, that open borders rectifies a glaring and morally problematic inequality of opportunity based on birthplace.
• The Rawlsian “veil of justice” argument is closely related.

Moral case from other hybrid and practical frameworks

• Bleeding-heart libertarian case, which combines the libertarian case with smatterings of utilitarianism and egalitarianism.
• Conservative and small-government case, which takes a skeptical attitude toward governments trying to exert fine-tuned control over who gets to immigrate.
• Human capabilities case, which argues for open borders within the human capabilities framework developed by Amartya Sen and Martha Nussbaum.

Generalized universalist arguments

In a blog post titled A Meta-Ethics to Keep in Your Back Pocket, Nathan Smith argues for open borders from a very generalized and minimalist universalist meta-ethic.

Confirmation bias? How do the libertarian, utilitarian, and egalitarian arguments all line up in the same direction?

Skeptics would be quick to point out how convenient it is that arguments from three completely different sets of moral premises: libertarian (predicated on natural rights), utilitarian/consequentialist, and egalitarian, all seem to point toward a similar conclusion. They might suspect that this is an example of confirmation bias at work. After all, in almost all day-to-day debates, the three philosophies give differing conclusions. How, then, this coincidence?

The answer is as follows. Yes, at the margin, there are interesting cases where these differing philosophies give differing answers. Most day-to-day political debates are focused on these margins. Further, interesting philosophical dilemmas and hypotheticals, such as trolley problems, are deliberately chosen to pit different moral philosophies against one another.

But when there is a massive violation of liberty, it is quite likely to be bad from both a utilitarian and an egalitarian perspective. Immigration restrictions are a massive violation of liberty (see the libertarian case) both in principle and quantitatively — large numbers of people who wish to move to another country are prevented from doing so by restrictive immigration policies. Another way of putting it is that immigration restrictions are a massive barrier to the free flow of labor, creating a place premium and preventing labor market convergence. As neoclassical economics would suggest, massive (as opposed to moderate) interventions in markets almost always have bad consequences in terms of utility and equality/fairness.

Further Reading

• “Aliens and Citizens: The Case for Open Borders,” Joseph Carens’s original article developing the multi-pronged moral case for open borders
• “Arguing for Open Borders,” a review of Carens’s ideas by philosopher Andy Lamey

The photograph of the demolition of the Berlin Wall featured in the header was taken by Gerard Malie for AFP/Getty Images.