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鈥淭he seventh billion [person] was added in 12 years, and that could be the story for the eighth billion 鈥� and that gets people who think that growth has stopped,鈥� said Carl Haub, senior demographer at the . Haub was joined by Hania Zlotnik, former director of the UN Population Division, and Rachel Nugent of the University of Washington鈥檚 Department of Global Health on June 5 to speak about the assumptions behind the . While each of the panelists noted the utility of projections, they also cautioned against seeing them as inevitable.

Meeting the Projections

As a former top official in the UN鈥檚 Population Division, Zlotnik spoke about how much is riding on the projections. 鈥淭he experts tell me that to , living better than the standards of living that we have today, one needs to increase agricultural production or all the production of food by about 70 percent and that is a challenge, but it might be feasible. But if the numbers go higher鈥 think it鈥檚 impossible,鈥� she said. 

The medium variant projection by the UN that gets the world to that nine billion figure is not a given 鈥� it builds in expected action on and improvement of many demographic indicators. Zlotnik pointed to the global , for example, which 鈥渋s especially high in the high fertility countries,鈥� and suggested that the current rate of increase in contraceptive use is insufficient. 

She calculated the number of years it would take many of these countries to meet their unmet need at their current rate of uptake and found 鈥渢he number of years for a lot of these poorer countries that have high fertility would be very long 鈥� 40 years, some of them, 80 years, 100 years 鈥� because the increased contraceptive prevalence has been so small.鈥� At that rate, population growth in these countries will far surpass the .

The perception that population growth is no longer an issue contributes to the problem, Zlotnik said. People see that only 18 percent of the world population lives in countries with high population growth and assume 鈥渢here鈥檚 no longer a population problem.鈥� But she emphasized the power of exponential growth, arguing that even a small proportion growing at a rapid rate can have a large impact. 

Questioning Assumptions

Haub pointed out several instances where assumptions in the methodology behind the projections create uncertainty. 

For example, there is a lack of data in many low-income countries. 鈥淎 date, let鈥檚 say 2000, 2005 鈥� it鈥檚 the past, but it may be a projection. It may be based on a census in 1990,鈥� he said. If it鈥檚 wrong, that error may not be corrected until another census, but it will still be relied on for country-level projections. 

He also noted that certain assumptions about desired family size sometimes do not bear out on the ground. One of the key methods to slowing population growth is to provide women and couples with the how many children they wish to bear. But in many fast-growing countries, women . In Niger, for example, women say their ideal family size is over nine children. Such women are less likely to use contraception, no matter how accessible it is, as they value larger families.

鈥淚t has been 鈥� I guess conventional is a good word 鈥� to assume that birth rates are going to come down the way they did in the rich countries,鈥� Haub noted. But there has been a 鈥溾�� for many developing countries, which he suggests is caused by fast initial uptake from urban women followed by much slower uptake by rural women. These dynamics, however, are relatively new and therefore are not always well incorporated into current projections.

The Economic Impact of Population Changes

While Haub and Zlotnik looked at the assumptions made before the projections are made and the importance and means to reach these projections, Nugent focused on the economic implications of lower fertility and the .

She suggested that increased control over fertility can positively impact a country鈥檚 economy. Women are given the opportunity to 鈥渋nvest their time in acquiring skills and investing time in the  and that affects their earnings鈥and] their ability to control resources and make decisions within the household鈥� as they spend less time caring for children, she said.

The labor market changes as well, as fewer children are born into a given generation. This can reduce 鈥渄emand on economic resources [and] demand on environmental resources,鈥� and the increased investment in human capital allowed by smaller family sizes can lead to a healthier population.

Nugent concluded by pointing out key areas of intervention most likely to decrease both fertility and mortality and allow countries to reap the positive economic benefits of fertility decline. She suggested a focus on 鈥渃omplementary investments in and ,鈥� especially with regard to 鈥減oor and marginalized populations,鈥� which can in fact impact the country as a whole. Finally, she recommended focusing on proven 鈥� [and] .鈥�

Educating Policymakers

Each of the panelists cautioned against relying on population projections without taking action to make them come true. 

鈥淢aybe the best thing to do if you鈥檙e giving a presentation is to show the  first and scare people half to death and then say, 鈥榖ut if 117,000 things go right, [the medium variant projection] is what will happen,鈥� said Haub, addressing the common tendency to view the UN projections as destiny. 

Similarly, Nugent warned against viewing the demographic transition as inevitable. 鈥淭here鈥檚 a certain sense鈥� that [the demographic dividend] is kind of an automatic thing that happens, and that really has to be addressed,鈥� she said, adding that 鈥渋t鈥檇 be quite interesting to show some scenarios of what would need to be done鈥n order to get some benefits from that dividend.鈥� (See also Elizabeth Leahy Madsen鈥檚  about this very topic.)

Zlotnik reiterated that the UN does not in fact know what the future will bring. 鈥淚t鈥檚 not that we know what the world is going to do, but we hope that [the projections] will get the message out 鈥� if this doesn鈥檛 happen, .鈥�