The question of open borders divides libertarians as much as any. The arguments for open borders made by the likes of Bryan Caplan, Alex Tabarrok, Don Boudreaux and Sheldon Richman are in many ways quite appealing. Fewer borders means greater opportunities for gainful trade among individuals. For the U.S., the economic gains from in-migration have been unquestionable. From a pure libertarian perspective, governments should never interfere with the non-violent actions of free individuals, including freedom of movement. These great economists contend, in effect, that there is no real moral distinction between government actions that confine individuals within borders and those that keep people out, though our conciences are less burdened by the latter because the world abroad seems so large.

There is a gnawing contradiction in this viewpoint, however. It relates to the appropriate scope of “ownership”. At the link above, Caplan says:

“The only principled libertarian objection to this is that the citizens of each country are its rightful owners, so they’re entitled to regulate migration as they see fit. … But if you believe this, there is no principled libertarian objection to any act of government. Fortunately, the belief that citizens are countries’ rightful owners is crazy. The social contract is an utter myth. Contracts require unanimous consent, and no country has ever had unanimous consent.“

The Character of a Good

I contest Caplan’s assertion that any one act of government is like all others. Yes, there is always a danger of a majoritarian tyranny in any democracy. But there is also the question of sovereignty, for which borders of some kind are necessary. If policies governing those borders are established legislatively, they should be subject to checks and balances: executive consent as well as judicial review of disputes.

I also contest Caplan’s statement that ownership implies unanimous consent. In fact, there are many forms of property over which decisions do not imply unanimous consent of joint owners. One such form is the subject of what follows, and I believe that form of “ownership” is applicable to one’s citizenship or residency status.

To keep things simple, I’ll frame this discussion only in terms of citizenship. I therefore abstract from issues like green cards, visiting worker programs, and the presence of resident aliens in general. For a nation, the essence of barriers to immigration can be addressed by considering the simpler case of citizens versus non-resident non-citizens. For purposes of this discussion, if you are allowed to arrive on a nation’s shores, you will be a citizen.

If a country’s citizenship can be considered a good worth acquiring, what is its real character? It is privately possessed and not tradable, but not all goods are tradable. An important taxonomy of goods in the public finance literature is based on two dimensions: exclusivity and rivalrousness. The former is the degree to which other parties can be excluded from enjoyment or use of the good or resource.

Most goods have at least some degree of exclusivity: you can be denied admission to a concert, the use of an appliance or furniture, and even parks and port facilities. Pure public goods like national defense and the air we breath are completely non-exclusive, however. Broadcast television is non-exclusive as well, as long as you have the equipment to watch it.

Rivalrousness is the degree to which the use or enjoyment of a good precludes another’s use or enjoyment. My friend can’t eat the steak if I eat the steak. That’s rivalrous. But my friend and I can both enjoy the concert. That’s non-rivalrous. A private good is both exclusionary and rivalrous. A public good is neither.

Citizenship as a Good

Citizenship can be viewed as a bundle of attributes much as any good, but it is an extremely complex bundle: it includes the individual rights enshrined in a nation’s constitution (if any), the personal and economic opportunities available by virtue of access to in-country markets and resources, the culture(s), and any personal risk reduction provided collectively, i.e., a safety net via public support. How, then, would one classify citizenship, or its component attributes, in terms of exclusivity and rivalrousness?

First, the entire citizenship bundle has a high degree of exclusivity. A nation can decide on closed borders, or partially open borders, if it chooses to do so, just as a theme park limits its gate. That is the political decision at hand. The degree of exclusivity of individual components of the bundle matters little if the bundle itself is highly exclusive.

At a high level, citizenship itself is non-rivalrous. My citizenship does not preclude citizenship for anyone else. Therefore, at the level of the bundle, citizenship is exclusive but non-rivalrous, so it has the character of what economists call a “club good“. Citizens are already part of the club; to that extent they are joint “owners”. Like many clubs, decisions about new membership need not be unanimous.

Classification of citizenship attributes as goods is trickier. The exclusivity of citizenship makes the non-rivalrous public goods available to citizens into club goods. Once admitted, for example, you are free to engage in speech, practice a religion of your choice, own a weapon, and receive due process and habeas corpus without interfering with any other citizen’s ability to exercise the same rights. You get national defense and a judicial system. You have equality of opportunity to the extent that your pursuit of economic gain does not interfere directly with anyone else’s opportunities. On the other hand, the freedom of assembly is rivalrous to at least some extent, as we learned last year from events in Charlottesville, VA. In fact, there may be congestion limits to some of the other freedoms mentioned above. 

Access to a nation’s markets permits mutually beneficial trade to take place. An individual’s participation usually does not rule out participation by others, so it is essentially non-rivalrous. (In some markets the entry of new sellers may be limited and exclusionary.) Of course, a nation’s resources are scarce; exploiting them for gain or enjoyment necessarily prevents others from using the same resources. From the point of view of existing citizens, these resources are non-exclusive and rivalrous, and are therefore classified as “common resources”, subject to congestion effects, but they are still exclusive to those citizens. The key here is not whether there are gains from trade, but that there is some rivalrousness embedded in this citizenship attribute.

In addition to the basic rights mentioned earlier, the entire legal structure, regulatory apparatus, and the political process are complex attributes of citizenship. These bear on the limits of legal conduct: Can you buy or sell liquor on Sundays? Do businesses require licensure? Is abortion legal? And on and on. In a democracy, the ability to participate in the political process is non-rivalrous: it does not prevent others from participating. However, the range of possible outcomes of the process can also be viewed as an attribute, and these outcomes, as they are promulgated, are certainly rivalrous. If the “other” side gets extra votes, then the power of my vote is diminished. So the limits of legal conduct are exposed to political rivalry. In the case of open borders, a large number of citizens may not favor existing rules, regulations, and the allocation of public spending.

So the attributes of citizenship are mixed in terms of rivalrousness: Some are rivalrous but many are not. The citizenship bundle, at a more detailed level, is therefore a mix of club goods (exclusive but non-rvalrous) and some goods that are rivalrous. This is important, because under the classical description club goods are public goods provided privately; they are therefore under-provided from the perspective of social welfare and the Pareto criterion that a new citizens can be made better off without making any existing citizen worse off. That might not be the case in the presence of congestion effects.

Should a Club Good Be Unrestricted?

Citizenship has value at the margin to both existing citizens, who should be regarded as established club members, and non-citizens. The foregoing establishes that there are some private (exclusive and rivalrous) attributes attached to citizenship. Sometimes this is due to the impact of congestion on the provision of public goods. Patrick McNutt, in his survey of literature on “Public Goods and Club Goods“, summarizes some basic conditions under which public goods are provided by clubs:

“The public good is not a pure public good, but rather there is an element of congestion as individuals consume the good up to its capacity constraint. What arises then is some exclusion mechanism in order to charge consumers a price for the provision and use of the good. Brown and Jackson (1990, p. 80) had commented that the purpose of a club ‘is to exploit economies of scale, to share the costs of providing an indivisible commodity, to satisfy a taste for association with other individuals who have similar preference orderings’. For Buchanan and Ng the main club characteristic is membership or numbers of consumers and it is this variable that has to be optimised.“

Citizenship (or residency) is generally not price rationed, though there are certainly costs to the immigrant. I make no pretense here as to the determination of an optimal membership from a club or larger social perspective. My point is that rationing membership is a rational choice by club members, or citizens in this case.

Okay, I Like My Club

Tribal affiliations, and ultimately nation states, were a natural outgrowth of early competition for resources, especially when identifying threats from outsiders was a constant preoccupation. Territorialism was a byproduct, and with the establishment of agriculture, the peoples of these early societies probably identified strongly with their homelands.

Modern nation-states have evolved from those early patterns, and nations continue to differ in terms of language, culture, and governance. Successful nations are undoubtedly more liberal (in the classical sense) and open to trade and cross-border movement. Maybe one day all nations will be united under the principles of libertarianism… don’t count on it! For now, to one degree or another, a nation’s inhabitants have an interest in minimizing economic and political risks and retaining access to resources within their borders. I don’t believe that desire is irrational or immoral. If the inhabitants of a nation have a moral obligation to share their rights, wealth, and political process with all comers, then they must accept the possibility that their rights will be compromised, and possibly even complete upheaval. They suffer a loss of sovereignty and a loss in the expected value of their citizenship.

There is obviously no limiting principle to the open borders policy, as Tyler Cowen says. Existing citizens would be obligated to accommodate all those who land upon their shores, granting them the full rights and opportunities accorded to all other residents. Perhaps there would be economic gains in the short or long run, as most libertarians would predict. But perhaps there would be some losses along the way. Perhaps there would be political stability after a large influx of new residents, but perhaps not. And ultimately, perhaps changes in the political climate would feed back to the detriment of economic performance. One simply cannot say, a priori, how things would go. There are risks to the existing citizenry, and if they are obliged to accept those risks, those might well include having to feed, clothe and house new residents. There should be no absolute obligation to accept those risks. If the debate is about individual liberty, then surely imposing those risks via open borders would  abrogate the rights of existing citizens.

Addendum: A Note on the Goods Taxonomy

Given the two dimensions of goods discussed above, exclusivity and rivalrousness, goods are classified as follows:

• Private goods: exclusive and rivalrous;
• Public goods: non-exclusive and non-rivalrous;
• Club goods: exclusive but non-rivalrous: e.g., a concert;
• Common resources: non-exclusive but rivalrous: the air we breath; an aquifer;

Another category is sometimes defined: contestable goods, which have the character of public goods or even club goods when under light use, and are common resources when under heavy use. There is a difference between an empty park and a crowded park; or an empty road and a crowded road.

See ThoughtCo. for a good exposition on the taxonomy.