This blog is intended to go along with Population: An Introduction to Concepts and Issues, by John R. Weeks, published by Cengage Learning. The latest edition is the 12th (it came out in 2015), but this blog is meant to complement any edition of the book by showing the way in which demographic issues are regularly in the news.

If you are a user of my textbook and would like to suggest a blog post idea, please email me at:

Friday, April 21, 2017

Earth Day 2017

I participated in the very first Earth Day back in 1970 and it has become my tradition in this blog to revisit the talk I gave that day and see how things have changed (or not) over time. At the time I was just finishing my doctorate in demography at UC Berkeley and I accepted the invitation to drive down to Fresno State for their Earth Day festivities (and it was a very nice celebration). At the time the world's population was estimated to be 3.7 billion--a bit less than half of what it is today--but the growth rate was the highest the world had ever recorded. My message to the audience 47 years ago (yikes--has it really been that long!!) was not much different than it would be today:
It seems likely that if we don't change our ways the ultimate creditors of the world--our food resources, our water, our air, the quality of human life--all those things from which we have been so heavily borrowing, may just foreclose on us. Frankly, there are just too many people around, and if you don't think so now, you can wait another 30 years when there may well be twice as many people on this planet.
Fortunately, the birth rate did drop somewhat faster than we were expecting at that time and so 30 years later, in 2000, the population had increased "only" to 6.1 billion--not a doubling, but still a significant increase creating even more issues in terms of environmental impacts and questions of sustainability.
Population growth is not unilaterally responsible for pollution, but make no mistake, every additional person born into the world aggravates existing pollution problems and makes solutions more costly to  achieve.
Something must be done to check population growth and the sooner that goal is realized, the better off we will be both in the short and in the long run. Now, I have read letters-to-the-editor in the newspaper and I have talked to individuals who say that the will of God will prevail and that if we have faith we will avoid disaster; others place their faith in science fiction rather/or in addition to God and argue that, as in the past, future technological advances will spring us out of trouble. To these people I say that they may be correct, but I am not willing to wait and find out when there are things that I as an individual can do right now to actively encourage and support population control. 
The obvious issue was to lower fertility rates around the world, and I championed the cause not just of making birth control more accessible, but more importantly to create a social environment in which people preferred smaller families.  
We should definitely advocate for the immediate removal of all discriminatory barriers against women in education [remember that this was the first year women had been admitted to Princeton University] and in the professions. If you can get a woman out of the house and reward her with financial gain and social and economic prestige, then the social and economic costs of having additional children are going to increase for that woman and she is far more likely than ever before to prefer a small family. 
To be sure, there are plenty of reasons besides just the demographic ones for the existence of gender equality, but this is still a compelling issue in more parts of the world than we might wish to think about.

In the end, Earth Day is really about people, not the Earth. The earth will survive without us, but we can't survive without it. 

Thursday, April 20, 2017

Can the Sustainable Development Goals Lower Population Growth?

As we approach this year's Earth Day celebration, it is useful and appropriate to think about how far above the current level of 7.4 billion the world's population might grow. The latest projections from the UN Population Division show a medium-variant (their "most likely" scenario) population in 2050 of 9.7 billion with an increase to 11.2 billion by the year 2100. These are good demographers, of course, but we really have to hope that these projections are higher than what history will show. 

Wolfgang Lutz and his group at the Wittgenstein Centre for Demography and Global Human Capital in Vienna have suggested a different way to project the population. They call them multi-dimensional projections because instead of using just age and sex they also build in projected changes in other aspects of society--especially education--that can influence birth and death rates. In the 13 December 2016 issue of the Proceedings of the National Academy of Sciences (PNAS) they published projections that were built with the idea of the world meeting the United Nations' Sustainable Development Goals (SDGs). Several of those SDGs, if fully implemented, will lower both birth and death rates in predictable ways.
In the context of sustainable development, world population growth is sometimes called “the elephant in the room.” Many view it as one of the most important factors in causing environmental degradation and in making adaptation to already unavoidable environmental change more difficult (16–18). At the same time it is widely perceived as a politically sensitive topic (19), and indeed the 1994 International Conference on Population and Development explicitly opposed the setting of “demographic targets.” Fertility decisions are considered a private matter, with the role of the state being only to assure reproductive rights and to provide reproductive health services. It is presumably for this reason that the new SDGs do not mention population growth or fertility explicitly in any of the 169 targets. However, many of the goals and targets deal with factors that directly or indirectly influence fertility and thus population growth.
 Their projections produce the following results:
In this paper we endeavor to translate the most relevant of these goals into SDG population scenarios and thus quantify the likely effects of meeting these development goals on national population trajectories. The results show that meeting these goals would result in the world population peaking around 2060 and reaching 8.2–8.7 billion by 2100, depending on the specific SDG scenario (Fig. 1). This analysis quantitatively demonstrates that demography is not destiny and that policies, particularly in the field of female education and reproductive health, can contribute greatly to reducing world population growth.

In other words, there are strong positive reasons to make sure that all countries successfully implement the SDGs. It may help to save the planet (well, the planet will survive with our without humans--you know what I mean). That is a positive way in which demography might shape the destiny of human life on Earth.