We are facing a low-fertility future

Published March 27, 2024

The world is facing a low-fertility future. By 2050, more than three-quarters of countries will not have fertility rates high enough to sustain population size over time. The latest Global Burden of Disease Study (GBD) looks at past and future trends, which have major implications for societies and economies. We discuss the fertility research with Dr. Austin Schumacher, one of the study’s authors.

This transcript has been lightly edited for clarity

Rhonda Stewart: Welcome to Global Health Insights, a podcast from IHME, the Institute for Health Metrics and Evaluation. I’m Rhonda Stewart.

In this episode we’ll hear from Dr. Austin Schumacher as he talks about the latest IHME study focused on fertility.

The study forecasts future fertility trends and includes data on previous trends to create a comprehensive picture of how fertility rates have changed over time. The study finds that dramatic declines in global fertility rates will create massive changes in population patterns over the next several decades. By 2050, more than three-quarters of the countries studied will not have fertility rates high enough to sustain population patterns. These trends will produce a demographically divided world with distinctive differences between low-income countries with high fertility rates and high-income countries with low fertility rates.

These changes will be nothing short of transformative. Policymakers and national governments will have to navigate implications for health, economies, national security, and the environment.

Give us a brief overview of some of the key findings of the study.

Austin Schumacher: Some of the key findings in this study are, first of all, we see that the world is converging on a low-fertility future, where by 2100, we project that 97% of countries are going to be below replacement levels of fertility, which means that if they were to continue at this level of fertility over time, then there would not be enough babies being born to sustain their population size. Additionally, we see that the distribution of births in the world is shifting away from higher-income countries and into lower-income countries. And so the distribution of where people are being born is going to be dramatically shifting in the in the coming years.

Rhonda Stewart: What are some of the factors that influence the differences that you saw in those low-income countries with high fertility rates and high-income countries with low fertility rates?

Austin Schumacher: There are a number of factors that are at play here, so in countries with higher fertility rates, they are still declining over time. We’re seeing that these countries are declining at a slower rate, though, than in previous years for other countries that we’ve seen. So, in these countries, access to contraceptives as well as higher or more access to female education, are two of the main factors that influence these countries continuing to have their fertility rates decline. However, in higher-income countries where fertility rates remain low, we see that there isn’t much evidence for rebounding fertility rates to increase back up to replacement levels of fertility. In these countries, policies to support parents are very key and pro-natal policies to allow for people to actually have children and to economically be able to afford to have children are really important. But these policies so far have not shown to lead to rebounding fertility rates as much as one might hope. A lot more innovation is needed on this front.

Rhonda Stewart: Are there particular countries or regions that stood out to you in the results that you found?

Austin Schumacher: So, one region in particular that we that we looked into was sub-Saharan Africa, and we found that our projections show by 2100, over half of the babies born will be in this this region of the globe. And this is really important, because, well, I spoke about the shift of births into lower-income countries and sub-Saharan Africa in particular. This is one of the regions that is most susceptible to heat stress and climate-related crises in the future.

And additionally, these are some of the poor countries in the world, with some of the worst health outcomes. So, this is going to lead to a lot of potential issues that will need to be looked into and resolved. So, strengthening of health care systems. And one of the one of the topics I think will continue to be even more important in the future is migration, and making sure that there is an open discussion and open policies for facilitating migration in in a way such that people in these locations are able to move if needed, if the environment becomes inhospitable, for example. And allowing that to happen, I think, will be really, really important.

Rhonda Stewart: Tell us also a little bit about the pace of change that you saw related to fertility. The study covers 1950 to 2021. Obviously there have been massive changes over that time period. But tell us about what you’ve seen in terms of the pace of change related to fertility rates.

Austin Schumacher: One of the most, I would say, surprising to me, at least, factors in this study is that in the more recent years that we have collected new data for, so up through 2021, we see that the pace of these fertility declines is happening a lot faster than we had previously projected, and so that could be a little bit alarming, because the past projections that we had showed a fairly rapid decline in fertility. And we’re seeing this is actually starting to happen even more. Or it’s continuing to happen even more rapidly than we originally thought just a couple of years ago.

And so that’s one important thing to take into account as we continue to collect more data and look at the most recent numbers. So we’ve seen some countries like South Korea and Japan have come out with their fertility estimate or fertility rate estimates, and their counts of live births since 2021, 2022, 2023, and we’re seeing that those are continuing to be at very, very low levels of fertility. So, this is definitely an issue that is continuing to be more and more important.

Rhonda Stewart: Is there a way to know why these changes have accelerated even faster than might have been anticipated through previous studies?

Austin Schumacher: I think it’s hard to really pin down exactly why that’s the case. I think that a lot of the factors in these high-income countries that I was previously talking about have quite possibly worsened over these last couple of years at a rate that we weren’t necessarily expecting. And so with that being the case, all of these different factors could have been contributing to a much steeper, maybe not much steeper decline, but at least a faster decline than we had previously projected.

But I think that an important consideration here is that these projections that we’re coming up with – so past projections that we had previously come up with, and these current projections that we are making and presenting in this paper and the study – these have a lot of uncertainty associated with them, and no one really knows what’s going to happen in the future. I mean, in 2019, no one would have known that we were going to go through a global pandemic, right? And so any attempt to try to project these sorts of things into the future is going to have a lot of uncertainty, and there are going to be a lot of changes that could happen during this time.

So these projections that we’re creating here are not us saying, this is what’s going to happen, right? It’s saying, this is if we look at what is currently happening in the world. And we make a lot of assumptions about this, but this is a typical, if nothing were to change, this is what we might expect to see in the future, with a lot of uncertainty associated with it. This is what we’re projecting will happen. And so as we get new data and more data, we’re going to be able to continue to refine these projections. And one one more thing really quick: We also make sure that we produce forecasts that take into account a number of alternate scenarios, as well as to try to give a range of different possible kinds of futures that that could happen if different things were to happen going forward in the future. So I think that’s another important part of the study.

Rhonda Stewart: You certainly mentioned some factors that are already present, things like migration, things like climate change, and then, having those alternate scenarios allows you to think about how those factors may continue to influence these sorts of trends and, as you mentioned, none of us can predict the future. The study does look to the future, though – it looks out to 2050, it looks out to 2100. And so how can having that kind of information about the future be put to use now?

Austin Schumacher: These projections really show the extent and the gravity of the potential problems that we will be facing in the future. And I think that looking at these forecasts, seeing what could potentially happen, gives really important insight into what we can do, and government organizations, intergovernmental organization as well, to try to address these issues that will be popping up. And, like you said, this is happening at a faster rate than we had previously thought. So that also lets us know that these are issues that we can’t just sweep under the rug, and they will be coming to light a lot sooner.

So, migration is one where there’s a lot of debate right now, and I think that needs to continue to happen. There needs to be a lot more of a push to address these issues with making sure that people are able to move freely. And this will also have a lot of impact on these higher-income countries where their fertility rates are falling, and we see that their populations are aging and there will be a lot more older people in their in these countries, and fewer younger people to support them, which could lead to issues with labor shortages and other economic issues where migration could be a potential solution here, in facilitating the movement of working-age people. There are a lot of potential solutions to explore. And I think that with the pace that we’re seeing, these are going to be issues that we need to talk about now.

Rhonda Stewart: And what would you say is one main thing that people should take from this study?

Austin Schumacher: Well, I hope that everything that I’ve talked about are a lot of main things that people will be able to take from the study. But if I were to summarize everything, we’re approaching a world that is going to have a lot of forthcoming changes in it, whether that’s societal, economic, and this is something that if we go about business as usual there are going to be a lot of problems that we will need to address. And so no, going about business as usual I don’t think is going to be the best way of approaching the future. And yeah, we’re going to need to take steps to address all these issues that that I’ve flagged here.

Rhonda Stewart: Great, thanks so much, Austin.

Austin Schumacher: Great, thank you for having me. This is a great conversation.

The fertility research is the latest in the Global Burden of Disease Study. Led by IHME at the University of Washington, GBD features more than 11,000 researchers from over 160 countries and territories participating in the most recent update, and it’s the largest and most detailed scientific effort undertaken to quantify health trends. Details about the Global Burden of Disease Study and a wide range of GBD-related resources can be found here.