The World Needs More People? Really?

By Mike Koetting April 18, 2021

Several weeks ago, a headline in the Chicago Tribune caught my attention: “What the world needs now is more humans.” My antennae went up. It was so counter my basic belief, I was compelled to read it.

I was not even a little convinced. But it raised enough questions about the future to be interesting.

Facts

Let’s start with a few basic facts. You probably know world population has been on an exponential growth curve for some time. But have you really stopped to examine that curve? World population has increased since 1900 almost five-fold, from 1.65B to 7.7B. Even with few other facts, this should cause at least an eye-brow raise. It’s hard to imagine systems that can have five-fold flexibility without getting into trouble.

Not surprisingly, this is accompanied by a commensurate demand on all the other resources of the world.

Source: Population Matters from World Wildlife Federation data

The above chart hints at the environmental problems this is causing. The details are even more sobering, whether you’re talking about species extinction, melting ice-cap, pollution, or pick your poison.

What’s With This Article?

Tyler Cowen, the author of the article, does not provides much compelling argument to support the claim there is something the matter with lower birth rates. By his own admission the crux of his position is that he laments the “failure to take full advantage of the planet’s capacity to sustain human life.” This is a stunningly abstract concern, particularly given the very real possibility that we have already exceeded the planet’s longer-term capacity to sustain human life.

From one aspect, therefore, this article is more deserving of derision than commentary.  But my second and third thoughts were on the issues raised by the underlying patterns of population changes. Advanced economies are already experiencing fertility rates below replacement levels. Thus, absent immigration, they will see populations decreasing in the foreseeable future. Most of Asia—to my surprise—isn’t far behind, as is Latin and Central America. While this scarcely leaves me longing for more population growth, it is worth some thought as to what are the impacts of such a powerful dynamic running out of steam.

Before getting carried away, however, we should keep in mind that many of those impacts are a bit distant. There will be little to no impact on resource consumption in any relevant time frame. For openers, even with more modest fertility rates, population will continue grow for at least 50 years because of the number of potentially fertile women already on the planet. Global population will probably exceed 10 billion before we see the total number decreasing.

Moreover, so much of recent population growth has been in countries with much less resource consumption, even substantial drops in those populations would in itself have modest impact on global human consumption. Over a longer term, reducing world population will have a favorable effect on resource consumption, particularly since some of the largest reductions are in countries that are working on increasing resource consumption to improve their quality of life toward the standards of developed countries. But these changes are not going to reduce the need for considerable, more direct reductions in resource use, particularly in those nations using the lion’s share of resources. There is no getting off the immediate environmental hook from population changes.

This being said, given the global diversity in starting spots and intensity of trends, some effects will be more immediate and some will be in different directions.

Source:  United Nations, World Population Project, 2019

While these are projections, and include ranges of likelihoods, over the past 70 years or so, these projections have been relatively accurate. Even so, rojections for 80 years in the future leave room for interventions. But, absent catastrophic events, population trend changes require time. Nor is there any particular reason to believe that the fundamental factors driving the projected changes are likely to reverse. For instance, there are virtually no examples of fertility increasing as economies grow, medical care improves and women become more educated. It is prudent to assume these projections are very plausible.

In that case, growth in Africa will continue to top the chart, particularly Africa south of the Sahara. It is projected that by 2100, five of the ten largest countries in the world will be in Africa. (Only one, Nigeria, is currently in the top ten.) Unless conditions there improve—more economic growth and greater political stability—pressures for migration will continue to grow. Europe in particular should be thinking very hard about its response Migration issues could easily dominate mid-century European politics as more and more people try to get there from Africa. In fact, Cowen notwithstanding, it would be a useful investment for the entire world to foster a better Africa and slow population growth.

At the other end of the spectrum, are the areas that will—if projections are roughly correct—experience major short-term changes in the other direction. Eastern and Southeastern Asia is projected to see a 5 percent increase between now and 2050 and then a 25% decrease from the peak by the end of the century. This is driven by China, which could see almost a 30% drop in population. It is hard to image that changes of that magnitude wouldn’t be destabilizing, economically and politically.

Stable or declining population, at least in an era of advanced health technology, will also rearrange the existing population since the change is coming not from an increase in relative deaths, but from a decrease in births. This skews the population older, which creates difficulties in making the society work. Japan is already being walloped by this shift in their society. China is starting to see it, but is till 30 or so years away from its largest impacts.

All of which raises the question of whether immigration will be seen as something potentially useful in maintaining a country’s economic base, even as it threatens its cultural homogeneity. Neither Japan nor China has any history of immigration as a constructive force. So it is not obvious how they will react as it becomes harder and harder to support aging populations with a decreasing working age population. Maybe the future of automation taking away human jobs is something necessary to support aged populations.

A shift toward an older population is an issue even in countries like the US that are not necessarily experiencing a major population drop. Like every other developed country, fertility rates among native born citizens continue to drop. While the measure of fertility rate is surprisingly complicated, it is safe to say that US birthrates are at some of their lowest levels and materially below the replacement level. This is shifting the population older, which creates challenges.

For instance, in 2010 there were seven potential family caregivers for every 80-plus year old. By 2030, there will be only four. This is also reflected in the decreasing proportion of workers available to pay for Medicare. In 1980 there were four people of working age population for every Medicare recipient, By 2040, there will be only two for each Medicare recipient.

The US could consider increasing immigration to address some of these changes.  Unlike Japan, the US has a robust history of supplementing native born population with immigration. But in addition to the political problems, there is a logical problem. As long as fertility rates remain low the problem feeds on itself because people who are initially young immigrants will eventually become old Americans. (Historically, immigrants have higher fertility than native-born Americans, but eventually wind up with the same fundamental patterns. Of course, pushing a problem out for a generation or so still has advantages.)

In short, although world population will probably stabilize by the end of the century, we are still faced with serious environmental problems. In the meantime, the unevenness in population changes will create local problems that will undoubtedly spill over into other areas. It seems to me all this suggests a more global approach to both the issues of environmental and population changes would be useful. I would, however, not recommend anyone hold their breath on that happening.