While writing the section on free immigration for my forthcoming book, Libertarianism: What Everyone Needs to Know, I posted this as my Facebook status: “If you claim to care about the poor and support social justice, but you are not in favor of open immigration, I do not have to and do not take you seriously.”

A Facebook friend offered an interesting challenge to the libertarian position. In this post, I’ll give a brief overview of the libertarian view, and then explain and respond to that challenge.

Immigration restrictions cause poverty, misery, suffering, and death. Michael Huemer explains this with a thought experiment: Imagine starving Marvin heads to the market in search of food. Imagine Marvin has little to trade. Yet there are people in the market willing to trade food for whatever Marvin has. Imagine that in the absence of interference, Marvin will successfully get to the market, make the trade, and eat. However, now imagine that you forcibly prevent Marvin from getting to the market. You post guards to keep him out. Suppose this works. The guards continually capture Marvin and turn him away. As a result, Marvin starves and dies. In this situation, Huemer says, you have done something morally comparable to killing Marvin. His blood is on your hands.

We could alter this thought experiment. Imagine Marvin is not starving, but is instead desperately poor. Imagine that if Marvin makes it to the market, he will make various trades and instantly become ten to twenty times richer. Imagine Marvin will be able to send large amounts of money home and feed his entire extended family back in his poor village. However, again, imagine you pay guards to turn Marvin away. In this case, you do something morally equivalent to forcing Marvin to stay poor. It was not your fault he and his family were poor to begin with, but it is your fault that they remain poor.

In these thought experiments, you do not simply fail to help Marvin. Instead, you actively hurt Marvin by using violence to prevent him from making a trade with a willing partner. That is, your behavior is not morally equivalent to walking past a beggar without sparing some change. It is more as though you saw someone offering a beggar $5 to wash a car window, but you scare the beggar and the car owner off with your gun. Your behavior, on its face, is vile and despicable.

Here’s the challenge from my Facebook friend: Marvin has to use public roads to get to the market. Thus, Marvin cannot simply assert a right to get to the market. To get to the market, he must use public property. Just as I have the right to turn away homeless people from my property, the government has the right to turn away immigrants who are trying to get to the market to sell their labor. Immigrants invade public property.

I think this challenge is unsuccessful for a number of reasons. I will not go through all the reasons here. I’ll just discuss one.

Let’s think about what it takes for private property to be legitimate. Imagine that you own a small plot of land, say, 1/3 of an acre in the residential neighborhood of Lake Barcroft, Virginia. Other plots of land surround yours. Your land is connected to a road. (It doesn’t matter, for our purposes, whether it’s a public or private road). Now, suppose that for some reason, in one day, I purchase all the land—including the road—that surrounds your house. I immediately post “No Trespassing” signs and say I will shoot trespassers on the spot. I put a fence around all my property, and thus put you in a cage.

You are now trapped in your land. Let’s add that if you don’t trespass over my land, you will starve and die. (Or, if you wish, imagine that you have a small garden, and will just barely survive.)

Almost everyone who reflects on this scenario, regardless of ideology, concludes that my actions are illegitimate. While I am permitted to purchase the land surrounding yours, I cannot then use my property rights to trap you in your own property. There are a number of arguments one could use to get to this conclusion, but I won’t offer them here. I think the conclusion is intuitive enough.

Most people conclude that in a scenario like this, you are entitled to some sort of easement. That is, I am obligated to permit you to cross some portion my property at will so that you may get to the market, to work, etc., and not be imprisoned in your own land.

As private individuals, we have rights to acquire property in land. We are not obligated to let anyone use our land at any time just because he or she needs it. But, we are obligated to allow people right of way over our land if our ownership would otherwise trap them.

Now, back to the point about public roads. This same reasoning applies. Just as a private individual must grant easements to others rather than trap them, so governments must grant easements to others rather than trap them. A government cannot put a public road around the market and say, “Ha, ha! Now you can only come to the market with our permission! And we don’t grant you permission, so you must starve and die!”