A common argument against easy immigration is that it will overload our country and overpopulate the US to the point where we don’t have enough room to comfortably live next to each other. This is fueled by the notion that our country is already overpopulated. This is one of the most complicated issues to discuss because it involves many other issues, one being environmental policy and land property rights. But, I’ll briefly say a few things. First, the US is not that populated compared to most other countries. The US has a population density of 84 p/sq.mi, lower than the world average of 140, Singapore with 19,731, India with 1,007, and Japan with 871 p/sq.mi. I’m not saying every country should be as populace as Singapore, but the US is not even close to reaching its population capacity. It’s also important for environmentalists to realize that open borders would not increase overall world population, it would only change which country people are living in (more here, less there), so environmental concern is not relevant to this topic.
Second, once a society (including its govt) sets aside land for various purposes of ecological/environmental health (having enough trees to produce O2, etc.) and recreation/beauty (parks like grand canyon, etc.), the rest of the allocation of land resources can be handled by the self-correcting mechanisms of the free market and property rights. The price system and basic supply and demand would prevent severe overpopulation (from immigration) because, as a resource becomes scarcer, it’s price would increase, which then decreases the rate at which people consume said resource. Let’s say that we open our borders to let nearly anyone in (except known terrorists, etc.). We may see a large rate of people coming in during the first year because we have much available space to fit more people in and property prices are still low for poor immigrants, but this immigration rate would gradually decline as available land was taken up and property prices rise from the decreasing supply. As time goes on, poor immigrants would be less and less incentivized to come here if the cost of living and property prices rose to the extent that it cancels out their benefits from the higher wages that they would earn here. This pressure would be partially relieved by building “up” (tall buildings to fit more people per area) instead of sprawling out, but the general tendency would continue such that land becomes scarcer and property prices increase. Eventually, you would get to the point where net immigration rates stabilized to lower levels, or stopped altogether.
Now, you may think, “Sure, maybe self-correcting market mechanisms prevent overpopulation so that we don’t get to the point of a crisis. But, do we really want to live in a society where property prices (and possibly other prices) may increase from immigration? That would suck for me because I would have to pay more”. It’s true that there would be both positives and negatives in such a process. But, the positives far outweigh the negatives. IF we were going to evaluate the open borders policy based on the utilitarian strategy of maximizing net happiness and well-being for the greatest number of people, then we have to make such a calculation considering all people, not just some people. After all, we can’t just say that your life only matters if you were born within the imaginary line that is the US border, and that your life doesn’t matter if you were born outside it. Relatively speaking, the typical US native, even “poor” natives, are richer than the poor of the outside world who wish to immigrate here. If one poor immigrant comes here and their life is dramatically improved, and this only causes an incremental small negative effect on relatively rich natives via slightly higher property costs (due to one immigrant), the overall effect is a great net benefit for all people considered because you have a large benefit and only small costs. You can repeat this point for every additional immigrant which causes each incremental rise in property prices, and the result of net positive gains in well-being is reached each time so that it becomes true that the well-being gained from many poor immigrants coming here far outweighs the total costs from a rise in property prices that accompany them.
Note that I’m not advocating welfare or any govt services for immigrants, mainly because I believe that all such programs should be eliminated anyway, for everyone. I’m not even saying that you should actively help immigrants. I’m just saying that you shouldn’t forcibly stop them from moving here and trading with others. If someone from Guatemala wants to come here and trade with some native citizen, it would be wrong to stop them just because you don’t want more people near you. If the tax costs via govt services are your concern, we can talk about that subject separately, apart from the notion of whether or not immigration would lead to a devastating lack of resources and “room” from too many people.
To speak briefly on the topic of govt budgets and spending, we have to distinguish between immigrants who have citizenship and those that don’t. After all, it’s possible to let immigrants come here to live freely, but deny them citizenship and the associated voting rights that come with it. Only citizens can get welfare. So, if we have a policy of allowing free immigration to occur, but deny them citizenship, then there wouldn’t be any welfare costs for them to begin with. However, they would still get some govt services, like public schooling, since these services don’t depend on citizenship. This problem is the result of govt, not immigration. We shouldn’t punish innocent immigrants for the bad policies of govt which hands out free education services to everyone at taxpayer’s expense. Govt shouldn’t even be supplying education in the first place. But, even then, it’s difficult to determine net costs because immigrants not only consume schooling but also pay some taxes, including sales taxes, at the same time as not receiving certain benefits that most citizens are eligible for. To further alleviate cost concerns, only the first generation of immigrants tend to have net costs to the govt. The next generation, born and assimilated in the US, tend to have indistinguishable characteristics from natives. Those born to immigrants within our borders would automatically receive citizenship from the 14th amendment, and they would eventually be eligible for welfare, but this is no longer a problem because the next generation is no longer very poor; they would be like the rest of the native citizenry, and the situation would be just like that of our own native population growing in numbers.
Another way to address govt service costs is to require immigrants to sign a contract that denies eligibility for various services as a precondition upon immigrating here, regardless of whether or not citizenship is involved. This wouldn’t apply to their future generations that live here (and it wouldn’t need to since their future generations aren’t a net burden, only the first generation might be). This could address things like public schooling.
Lastly, some believe that immigration to the US would continue until the US is just as poor and miserable as the poorest and most miserable nation in the world. The theory is: as long as the US is a better place to live in comparison to the worst nation to live in, even just incrementally slightly better, then free immigration would result in people moving from the worst place to the better places. The process would only end and people would only stop leaving their miserable countries when the US and other first-world countries were dragged down to the same level of misery. Although this mechanism can occur to some small extent, there are many, many problems with this theory that prevent it from reaching its extreme fulfillment. It ignores all economic pressures that result from changes in population density and supply and demand, some of which I discussed above, that tend to resist extreme differences in concentrations of people from one country to the next. It also ignores how political forces would change in the “miserable” countries if such countries’ political leaders all of the sudden realized all their people were leaving (if they’re legally allowed to leave at all, that is). It also ignores the costs and difficulties of travel. And, it ignores factors that cause people to stay where they are instead of move. It’s generally difficult to leave your family and friends and a community and language system that you are familiar with. It’s always easier, all things being equal, to stay put instead of move. Typically, people only move if there are very good reasons to move, not just because a place far away is slightly better. The potential increase in well-being and standard of living have to be great enough to outweigh moving costs, being far away from family and friends and your original community, having to learn a new language, etc. The mere fact that a place is not pleasant to live in does not automatically result in all the people in that place moving to some other better place. A humorous example to illustrate this (don’t take this too seriously) is that many people still live in New Jersey (not a pleasant place), and not everyone lives in those nice southern states.