Author Talks: One billion more

The global population is fast approaching the eight billion mark. A former Department of Defense consultant says not to panic.

In this edition of Author Talks, McKinsey Global Publishing’s Raju Narisetti chats with Dr. Jennifer Sciubba, political demography expert and former policy consultant to the secretary of defense, about her new book, 8 Billion and Counting: How Sex, Death, and Migration Shape Our World (W.W. Norton & Company, March 2022). Since 1975, the population has increased by one billion people every 11 to 12 years, but the world has undergone widespread changes in the past decade—with new variables affecting fertility, mortality, and migration. An edited version of the conversation follows.

Our planet is nearing eight billion people. Why should we pay attention?

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I’m Jennifer Sciubba, and my book, 8 Billion and Counting: How Sex, Death, and Migration Shape Our World, is an overview of global demographic trends, but it’s also more because it teaches you how to read the world. A lot of what’s written about population is alarmist in tone, and it really politicizes population issues, which I think is a real problem because it can prevent us from meaningful reform on really important issues. One example of that would be migration.

If we look at the US, for example, that fear around migration has really infected politics to the point where it’s impossible for Congress to pass any reforms to migration that are really needed. In France, China, and a lot of other countries, too, the issue is infused with emotion because it’s so personal. “Population trends” sounds like this really large-scale thing, but at the end of the day it’s about individual people—just aggregated. Because emotion pervades so much of the discussion, we can’t get a lot of things done. What I try to do in the book is take that alarmism out and give a well-informed, social-science view on population trends to hopefully help us move past that.

The second reason I think the book is really useful is that we don’t hit these “billion” milestones very often—it’s only around every 12 or 13 years. The fact that we’re coming up on a planet of eight billion people for the first time ever gives us the opportunity to pause and take stock of who we are and where we are. It’s amazing because we still see unprecedented trends. In particular, the one I focus on a lot in the book is the great divide between richer and poorer countries in all three areas of population: fertility, mortality, and migration.

We don’t hit these ‘billion’ milestones very often—it’s only around every 12 or 13 years. The fact that we’re coming up on a planet of eight billion people for the first time ever gives us the opportunity to pause and take stock of who we are and where we are.

How and why do people misread demographic trends?

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There’s a misreading of demographic trends among policy makers, the media, and the average person, most definitely. A lot of that misreading comes from desirability bias, and it can really be dangerous. There is an example of this with Russia.

There have been a lot of policy makers over the last several decades who have seen what they want to see in terms of Russia’s population and how they thought it would affect Russia’s ability to project military power outside its borders. In particular, a lot of people know Russia has a very high mortality rate for men, and a very low fertility rate. At some points in recent years, Russia’s population has shrunk at a rate of about half a million people per year. Reading that in a “demography is destiny” mindset means you would think that Russia would be unable to project power outside its borders, as if there was this one-to-one ratio between population trends and national security.

But as I describe in the book, that’s not the case at all, and there are a host of other contextual factors that we have to bring into the discussion of demographics. These are in the political, social, and economic realms, and I think they can lead to a much more nuanced and more accurate read on trends in Russia, or even trends in China, for example. If we only see what we want to see with regard to those countries, we can be ill-prepared when their actual behavior differs from what we expect.

Is ‘waves of migrants’ a myth?

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A lot of people will be surprised to learn how rare migration is these days. The pop quiz that I give all the time when I’m speaking to different audiences is, “What proportion of the world’s population do you think lives outside the country in which they were born?”

Answers always overestimate it, even among expert audiences: they’ll say 50 percent or 20 percent, but the right answer is just 2 to 4 percent for the last 50 or 60 years. Migration is rare. Most people stay where they’re born.

I think recognizing that is really important for several reasons. One is that the message of, “Waves of migrants are coming in the future,” can actually lead to inaction in the present because it leads people to think, “If this is a certainty and there will be lots of migrants coming, we don’t have to do a lot.”

Here’s an example of that: for businesses leaders who might be hoping to rely on immigrants to fill their workforce in countries with population aging—there are a lot of countries whose populations are aging, and their workforces are shrinking—they might be really surprised and disappointed to see that those waves of migrants aren’t coming. That means they need to take some action now in order to shape the workforce that they want in the future. That’s an overestimation of migration, which I think can be really dangerous.

There’s another way that migration is overestimated, and that’s related to the pressure surrounding refugee crises. What I mean is that waves of refugees are likely to be an issue in the future, but the way that the media or policy makers portray the coming waves of refugees—showing up at the shores or on the borders of the West from far-off areas experiencing conflict—is inaccurate because the demographic pressure to migrate is there, but politics [of immigration] is the ultimate gatekeeper.

I think what is missing from all of these accounts that overestimate migration is the political element. I’m trained as a political scientist, so what I try to do in the book is really bring that front and center. We are overestimating the impact of the waves of migration—the waves of refugees. They will show up, but we forget how much control states actually have over their borders. We can see that all the time.

Fewer than one percent of migrants annually—people who have been displaced, particularly refugees—have actually been resettled in a third country over the last several decades. Very few people are actually officially resettled as migrants. The West is not going to be overrun with refugees, because politics [of immigration] is the gatekeeper there.

Here’s where the underestimation comes in: we don’t have systems in place at the global or national level to deal with the tremendous pressure [caused by migration], which we see with the displacement [of people] from Ukraine, Venezuela, and many other areas of the world today. The pressure will be there, but politics will be the gatekeeper.

Fewer than one percent of migrants have actually been resettled in a third country over the last several decades. Very few people are actually officially resettled as migrants. The West is not going to be overrun with refugees, because politics [of immigration] is the gatekeeper there.

Are we headed toward being a planet of huge, urban slums?

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One of the real fears that we have with population trends today is that urbanization trends won’t lead us to shiny, sparkling cities filled with skyscrapers but instead might lead us to a planet of slums. Research-wise, we still have a lot to learn about urbanization’s effects on politics and on the economy.

In part, that’s because our past waves of urbanization seem to be different from the urbanization waves that we’re facing now. We know that there are all kinds of forces—climate change would be an example of this—that push people out of rural areas in countries that are not yet highly urbanized.

These forces push people out of rural areas and into urban ones, but in the past, urbanization often took place because people were pulled into urban areas by job opportunities. These are two very different things. When hundreds of thousands—or even millions—of young men, in particular, are pushed out of rural areas and into urban areas and they don’t find jobs, then we rely on our other political-science research to understand what that means in terms of politics.

A lot of times, what that leads to, is instability. There’s a low opportunity cost, for example, of joining a rebel group because there’s not much to give up if you are not employed. I would love to see a lot more research and thinking, even in the private sector, about what economic structures are like in countries that have yet to urbanize or are at the beginning of urbanization, because you don’t see the same level of manufacturing or formal employment that we have seen in past waves of urbanization.

I think what that actually means is that there is a lot of opportunity for creativity and innovation in the private sector to harness that large, urban population as an asset for economic development. We don’t see that yet, but I hope that reading the book would give those sectors some ideas about ways to make the most of their population as a resource.

I would love to see a lot more research and thinking, even in the private sector, about what economic structures are like in countries that have yet to urbanize or are at the beginning of urbanization, because you don’t see the same level of manufacturing or formal employment that we have seen in past waves of urbanization.

How can demography help policy makers?

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One of the coolest things about demography is that it’s a window to our past and a window to our future. It’s the closest thing to a crystal ball that we have. It’s really hard to do long-term trend analysis, such as “What’s the stock market going to do in a week from now?” We have no idea. But what’s nice about population is that the future is baked into the present because tomorrow’s retirees are today’s workers, and tomorrow’s mothers are today’s kindergartners. Any snapshot of a population today tells us a little bit about the future.

Trends do change, of course—and I describe a lot of the ways that they change in the book—but they generally follow predictable patterns. They can be really useful for long-term businesses planning, which underscores the idea that we have to invest today to shape the future that we want tomorrow.

One example of that might be thinking about the workforce. We know that countries like Vietnam and Thailand are rapidly aging—their populations are growing older from decades of low fertility and longer life expectancy.

If those countries want to have adequate workforces in the future to keep fueling their economic growth, one of the things that they need to invest in today is the health of the population because the longer people are able to be healthy and stay in the workforce, the more useful they are in terms of an economic resource.

That’s a very utilitarian point of view, but we could change it to an individual point of view: we all want to live as long and healthily as possible, so it’s about the idea of investing in health infrastructure today so that the gap between how long someone lives, and how long someone is healthy and living, narrows. We can live longer, healthier lives that way.

What’s nice about population is that the future is baked into the present because tomorrow’s retirees are today’s workers, and tomorrow’s mothers are today’s kindergartners. Any snapshot of a population today tells us a little bit about the future.

What surprised you most in researching and writing this book?

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Even though I have been writing, researching, and speaking about these population trends for my entire career, I was still surprised in writing the book because I realized just how much population trends are converging worldwide.

One of the things I’ve really been thinking about is that trends change quickly, but our thinking doesn’t always change to keep up with it. I can actually turn that back on myself and realize how much I was stuck in population trends that were predominant about ten years ago.

For example, it’s true that there’s a huge divide in terms of fertility, mortality, and migration in the world today between rich and poor countries. I do use that to give the book a coherent frame, but as I’m describing this, because population is a window to our future, I can already see that we’re coming back together. We’re converging to be a world of aging populations with longer life expectancies and relatively healthy populations.

I think that was a surprise for me because so much has changed in terms of how quickly fertility lowered in many places where it was really high over the last couple of decades. The Sahel region in sub-Saharan Africa still has high fertility, but in many other regions in sub-Saharan Africa, fertility has gone much lower. We also see the spread of population aging all around the world, and that wouldn’t have been the case when I was doing my dissertation, for example, quite a while ago, or when I was writing my first book.

When we go to take stock of a world of nine billion people, I don’t think it will look the same way it looks for a world of eight billion people. I think there are always going to be regions of the world that are relatively poorer than others, but I think it will be a story of trend convergence, and that will be really interesting to watch.

Watch the full interview

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Jennifer Sciubba on adding one billion more people to the global population

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