Can the World Have Both Rapid Population Growth and Sustainable Development? by David Lam & John Bongaarts

This is part of an online discussion, a point/counter-point exchange on the issue of rapid population growth and sustainable development. The debate continues on what the international development agenda should be. These arguments are just as relevant to U.S. family planning services as to any other country.



The Quantity/Quality Transition

David Lam:

When couples decide whether to use contraception and whether to have another child, they think not only about the numbers of children but also about the quality of life each child will have. As fertility has fallen rapidly in most regions of the world, the amount of resources invested in each child has also increased dramatically. Some of these investments, such as schooling and public health, are at least partly provided by public resources. But many of the investments are made by the parents, and explain why parents around the world talk about children being more expensive than they were when families were much larger. In the last 50 years most of the developing world has made a transition from couples having large numbers of children with low investments per child, to couples having small numbers of children with high investments per child. This is one of the most fundamental dimensions of economic development and is one of the reasons for optimism about the future of the world. Children born today in developing countries will be healthier and better educated than their parents or their grandparents, good news for them and for the countries they live in.

...or Quality?

…or Quality?

Economists think of parents as choosing both the quantity and the ‘quality’ of children, in the same way that people choose both the quantity and quality of things like cars, houses, and clothing.  Non-economists sometimes find this language offensive, perhaps because it sounds like some children are more valuable than others or because it equates children with consumer durables.  But ‘quality’ of children simply refers to the amount of resources invested in each child, with these investments resulting in outcomes such as better health, more education, and a higher standard of living. Parents make decisions about both quantity and quality, and it is important to keep this in mind in thinking about why parents choose to reduce fertility. Whenever we see fertility decline we also see increased parental investments in children. It is really the combination of lower quantity and higher quality that parents are choosing, not simply lower fertility.

Understanding this ‘quantity-quality transition’ is important in thinking about population policy. Parents choose a combination of lower quantity of children and higher quality of children for a number of reasons. One reason is because increased child survival makes this a more viable childbearing strategy. Another is because better access to family planning services gives women the ability to choose a low fertility option. Another important reason is because with economic development parents begin to see increased returns to investing in their children.

Urbanization and industrialization bring increased returns to human capital, including education and health. Parents begin to see that a child with good schooling can do well in the world. This is one of the reasons why parents move to a strategy of low fertility and high investments in their children.

Women are most likely to reduce fertility when they see rewards to increasing investments in children. Family planning programs are most likely to be effective when they are accompanied by improvements in schools, better economic opportunities, and improvements in child survival. Most countries have already made the transition from high fertility-low investments to low fertility-high investments. The challenge is to bring this transition to the remaining poor countries, mainly in Africa, that have yet to make it. The best way to accomplish this is to provide access to family planning that is accompanied by policies and programs that will improve economic growth and increase the returns to investments in children.

John Bongaarts:

Economists have made important contributions to our understanding of the fertility transition by emphasizing the crucial role of investments in the education and health of children and by analyzing the quantity-quality trade-off that parents face when making family size decisions. Poor countries should indeed make education and health improvements a top priority. This will yield many individual and social benefits and will eventually bring about the fertility transition. However, such transitions take time and will leave many poor countries with huge population increases that threaten to derail development. This is why family planning programs are also essential.

Unfortunately economists have been largely unsupportive of family planning programs. As David Lam points out, economists think of parents as choosing both the quantity and the ‘quality’ of children, in the same way that people choose both the quantity and quality of things like cars, houses, and clothing. An obvious problem with this way of thinking is that durable goods require an active purchase in the market, while pregnancies occur unless an effort is made to avoid them. In addition, economic theories typically assume that the cost of contraception is sufficiently low to be ignored. From this academic perspective the occurrence of unwanted pregnancies should be as rare as of unwanted new cars; family planning programs are therefore considered pointless and a waste of resources. Needless to say, the real world is different.

Richard Easterlin recognized the problem with this reasoning and in the 1970s produced an influential revision of the conventional economic theory of fertility. His framework for the determinants of fertility added two critical elements. First, it acknowledged the role of biology in childbearing outcomes. Specifically, without efforts to control conception, women who are sexually active would bear large numbers of children, because a pregnancy takes only nine months and the reproductive years last decades. To avoid having ‘excess’ children, parents must practice birth control. This fact makes the ‘acquisition’ of children fundamentally different from the purchase of durable goods. Second, Easterlin recognized that the cost of birth control could be substantial, thus leading to significant numbers of unplanned pregnancies. These costs are broadly defined to include economic, health, psychological, and social obstacles.

The opposition of economists to family planning programs has been one of the main reasons for the low investment in them during the past. Fortunately the tide is now turning and Easterlin’s views are taken seriously again. Not a moment too soon.


John Bongaarts, Ph.D. is Vice President and Distinguished Scholar of the Population Council in New York.  Mr. Bongaarts is the author or co-author of approximately 200 scholarly articles on various aspects of demography, including the determinants of fertility, population-environment interactions, the demographic impact of the AIDS epidemic, population aging, and population policy options in the developing world.  He is a member of the Royal Dutch Academy of Sciences and the US National Academy of Sciences, and a fellow of the American Association for the Advancement of Science.  

David Lam, Ph.D. is Professor of Economics and Research Professor in the Population Studies Center, University of Michigan.  He was President of the Population Association of America in 2011.  Throughout a long and distinguished career, Professor Lam’s research has focused on the interaction of economics and demography in developing countries, including analysis of the economics of population growth, fertility, marriage, and aging.  He is currently on sabbatical at the University of Cape Town.

2 responses to “Can the World Have Both Rapid Population Growth and Sustainable Development? by David Lam & John Bongaarts

  1. Oh sure we can, but not while having a lot of extremely rich people. We can have two out of five. Choose.

    – a really bright long term future as a species on the planet, and beyond 2050 off the planet, making some difficult sacrifices…
    – unbridled population growth, breeding, famines, massive instability, epidemics, maybe even wars…
    – capitalism and some obscenely rich people world wide with everyone else doing less well than now…
    – global peace, democracy, freedom, happiness for most people, but at sharply reduced affluence levels because we go full on sustainable…
    – consumerism, cars, massively bloated cities, bigscreen TV’s, current diets, agriculture business, business as usual…

  2. monk

    Unfortunately, in a global capitalist system, the latter is dependent on the former.

Leave a Reply