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 13th (it will be out in January 2020), 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.

You can download an iPhone app for the 13th edition from the App Store (search for Weeks Population).

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

Monday, July 16, 2018

How Important is Demography in American Politics? Part Two

One of the emerging issues in the increasingly polarized politics of the United States is the demographic divide being created by where people live. In the current configuration of the Republican and Democratic parties, Republicans tend to live in the suburbs and in rural areas, whereas Democrats tend to live in or near central cities. In theory that shouldn't matter when it comes to election time, but this week's Economist provides a civic lesson reminding us that the founders of the U.S. Constitution set up a system that effectively gives greater per-person electoral power to people living in less densely settled areas.
The source of this discrepancy is that Democrats will win their seats with big majorities in fewer districts, whereas Republicans will prevail by narrower margins in a larger number of districts. In 2016 Democrats who beat Republican opponents won an average of 67.4% of the two-party vote in their districts, whereas Republicans who defeated Democrats received an average of 63.8%. This imbalance is partly due to deliberate attempts to create districts that provide such results, and partly just down to the fact that Democrats tend to live more tightly bunched together in cities. Together, these two factors put up quite an obstacle. According to our model, the Democrats need to win 53.5% of all votes cast for the two major parties just to have a 50/50 chance of winning a majority in the House.
If this imbalance were limited to a single chamber of the legislature, or a single election cycle, the Democrats’ frequent carping about a stacked electoral deck might sound like sour grapes. All electoral systems have their oddities. But changes in where Americans live and contradictions in their constitution—a document designed to work with many weak factions that has instead encouraged and entrenched an increasingly polarised two-party system—have opened gaps between what the voters choose and the representation they get in every arm of the federal government. In recent decades these disparities have consistently favoured the Republicans, and there is no reason to think that trend is going to change on its own.
There are three underlying issues here. First, the Senate is deliberately set up so that each state has the same number of senators in order to keep the heavily populated states from dominating that chamber in the way that they can the House of Representatives. That aspect of the system is unlikely ever to change, even though a senator from Wyoming (the least populous state with scarcely more than a half million people) represents fewer than 300,000 people whereas a senator from California (the most populous state with almost 40 million people) represents 20 million persons.

Secondly, with respect to the presidential election, we have this strange thing called an electoral college system:
In all the world’s other 58 fully presidential democracies—those in which the president is both head of state and head of government—the winning candidate gets the most votes in the final, or only, round of voting. But due to the “electoral college” system that America’s founders jury-rigged in part to square the needs of democracy with the demography of slavery, this does not hold true for America. States vote in the college in proportion to their combined representation in both houses of Congress. This set-up means that a candidate who wins narrowly in many small and smallish states can beat one who gets more votes overall, but racks most of them up in big majorities in a few big states.
This could be changed, at least in theory, as could the third issue--gerrymandering of districts for the House of Representatives (as well as for many state and local issues). There has been a lot of action on this front, although most recently the Supreme Court has punted

Sunday, July 15, 2018

How Important is Demography in American Politics?

This week's Economist has a lengthy special report on American politics, focusing especially on the identify politics that have emerged in the widening gulf between Republicans and Democrats in this country. And how could I resist not talking about this article when the author's acknowledgments include being in debt to several prominent demographers whose names have appeared in my book and blog: Bill Frey, Steve Murdock, and Dowell Myers. Indeed, Bill Frey and Dowell Myers were featured in my blog post just a week ago

The article picks up on the fact that many observers over the years have assumed that as racial/ethnic diversity increases in the U.S. the Democratic Party would benefit more than the Republican Party because the assumption was that Democrats had a political agenda more to their liking. Indeed, there has been a lot of speculation that these kinds of analyses helped to spur on the fears of losing "power" among non-Hispanic whites, helping to propel Donald Trump to the presidency. As I noted last week, Dowell Myers has suggested that the old race-ethnic categories that most of us have been using forever hide the fact that a lot of intermarriage has been going on that has led to people identifying themselves as "white" even though they may indicate on a census questionnaire that they are of more than one race. And, of course, this kind of discussion always reminds me of the very interesting article by Mara Loveman and Jeronimo Muniz: "How Puerto Rico Became White: Boundary Dynamics and Inter-Census Racial Reclassification." American Sociological Review 42(6): 915-939, (2007). Sadly, after Hurricane Maria there were a lot of people on the mainland who didn't even want to acknowledge that Puerto Ricans were Americans, much less white Americans...

Of particular interest in the Economist article is that one of their story lines is that "Demography is not Destiny." This is actually an about-face for a magazine that has probably used the phrase "demography is destiny" more than any other that I know. In this case demography refers to the population characteristic of "race-ethnicity" and the discussion is about the extent to which our self-identified race-ethnicity determines how we think about the world. The best answer is that this is complicated. Race-ethnic categories are social constructs, in the first place, and the whole idea of the American experience is--as the Economist author ends the story--e pluribus unum: out of many, one.

Thursday, July 12, 2018

Is the World More Urban Than We Thought?

I spend a lot of time at the beginning of my chapter on "The Urban Transition" on the ways in which "urban" is defined around the world. Indeed, we usually think of it as a dichotomy between urban and rural, whereas I suggest we really should think of it as a continuum or a gradient. One of my recent PhD students, Dr. Magdalena Benza, implemented such a measure using our data for Ghana and a paper from that research was published last year in the journal Population, Space and Place. The United Nations Population Division tends to define urban as a dichotomy based on the definitions of urban used by member nations. By those criteria the world's population is currently more than 50% urban and will be about 2/3 urban by the middle of this century.

But, wait a minute! What if those estimates by the UN are too low? Thanks to another of my former PhD students, Dr. Debbie Fugate, for linking me to an article today from Reuters discussing the European Commission's new methodology for defining urban populations based on the classification of satellite data. Now, to be sure, the headline of this piece--a quote from the European Commission researchers--is a bit dramatic: "Everything we've heard about global urbanization turns out to be wrong." That's a bit of an exaggeration, but the use of satellite imagery does give us a different perspective, as I and my colleagues have seen, and as a good friend of mine, Dr. Deborah Balk at CUNY has also been discovering for a long time.
Using a definition made possible by advances in geospatial technology that uses high-resolution satellite images to determine the number of people living in a given area, they estimate 84 percent of the world's population, or almost 6.4 billion people, live in urban areas.
"Everything we've heard about global urbanization turns out to be wrong," said lead researcher Lewis Dijkstra.
Asia and Africa, which are routinely cited as majority-rural continents that are rapidly urbanizing, turn out to be well ahead of figures in the U.N.'s latest estimates. Once thought to be about 50 percent and 40 percent urban respectively, the new research argues Asia and Africa are closer to 90 percent and 80 percent, or roughly double previous estimates.
Those percentages translate to billions of additional people living in cities and urban areas, such as towns and suburbs, than previously thought. "If this is true, the impact is going to be massive," Dijkstra said. "A lot of development aid was geared toward rural."
The reason for the past errors is simple, Dijkstra said, because countries self-report their demographic statistics to the U.N. and they use widely different standards.
So, the researchers at the EC derived their own consistent definition: 
According to the European Commission definition, any contiguous stretch with at least 50,000 people and a population density of 1,500 per square km is considered an urban center. Any area with at least 5,000 people and a population density of 300 per square km is classified an urban cluster. Rural areas are those with less than 300 people per square km.
You can appreciate, of course, that you can't actually count people from satellite images, so you're going to need census and/or survey data to go along with that. There's a lot of work involved here, and you can check out the European Commission's database here. You can also make your own comparisons with the UN data, which are found here. Keep me posted on what you find out!

Wednesday, July 11, 2018

World Population Day 2018

Today is World Population Day, the theme of which this year is "Family Planning is a Human Right." It is genuinely sad to think we have to keep emphasizing that point, rather than all of us just taking it for granted. Another thing we typically take for granted is being alive, but I missed last year's World Population Day celebration because I was in the hospital intensive care unit as a whole team of physicians (several of them immigrants, I should point out) saved my life when I came down with sepsis (cause still unknown). So, I am very grateful to be here thinking about the 8th anniversary of this blog. 

Back in 2010 the world's population was getting very close to the 7 billion mark (which we hit the next year in 2011). As of today, the Census Bureau's population clock estimates that we are at 7.5 billion. So, in the eight years that I have been blogging, we have added 500 million people to the planet (and, no, I am not to blame for that!). Other demographic trends have been moving in the right direction during this time. The UN Population Division estimates that since 2010 the world's total fertility rate has dropped from 2.57 to 2.47, while life expectancy at birth (both sexes combined) has gone up from 69 to 72. 

We have to remember, though, that the medium variant of the UN population projections suggests that the world's population will continue to grow until at least to the end of this century, and that takes into account expected declines in fertility and mortality. Those things are not likely to happen automatically, however. We need to stay active in the pursuit of those improvements in the quality of life all over the globe.

Tuesday, July 10, 2018

Getting Ready for World Population Day

Tomorrow (June 11th) is World Population Day, as proclaimed by the United Nations back in 1989. In preparation for that event, two very interesting articles have been posted to the Conversation. The first one is from Andrew Hwang, a mathematician at the College of the Holy Cross: "7.5 billion and counting: How many humans can the Earth support?" His ideas will be very familiar to you if you've read my book.
Humans are consuming and polluting resources – aquifers and ice caps, fertile soil, forests, fisheries and oceans – accumulated over geological time, tens of thousands of years or longer. Wealthy countries consume out of proportion to their populations. As a fiscal analogy, we live as if our savings account balance were steady income. According to the Worldwatch Institute, an environmental think tank, the Earth has 1.9 hectares of land per person for growing food and textiles for clothing, supplying wood and absorbing waste. The average American uses about 9.7 hectares. These data alone suggest the Earth can support at most one-fifth of the present population, 1.5 billion people, at an American standard of living.
A related article by Derek Hoff, an historian at the University of Utah (and author of a very interesting book titled The State and the Stork: The Population Debate and Policy Making in US History) focuses on the Neo-Malthusianism of Paul Ehrlich, but essentially draws the same conclusion as Hwang. The title of Hoff's article is "A long fuse: ‘The Population Bomb’ is still ticking 50 years after its publication".
“The Population Bomb” created more space to hold radical views on population matters, but its impact was fleeting, and maybe even harmful to the population movement. By the early 1970s, many critics were savaging Ehrlich and the larger goal of achieving zero population growth. And the politics of “morning in America” in the 1980s successfully marginalized Erhlich as a doomsdayer. 
But he got much right, even if many details and his timing were off. Global population has increased at a remarkably steady rate since 1968, and the United Nations projects that it will reach 9.8 billion by 2050 and 11.2 billion by 2100. Scientists continue to extend his prescient warnings that efforts to feed all these people through pesticide-intensive monoculture may backfire. And although Ehrlich exaggerated the threat of mass starvation, about 8,500 young children die from malnutrition every day.
Human-driven climate change is an overriding threat, and is unambiguously worsened by population growth. The Intergovernmental Panel on Climate Change estimates that limiting warming in this century to 3.6 degrees Fahrenheit (2 degrees Celsius) would require cutting global greenhouse gas emissions 40 to 70 percent by 2050 and nearly eliminating them by 2100. “Globally, economic and population growth continue to be the most important drivers of increases in CO2 emissions from fossil fuel combustion,” the panel observes.
The point of both articles is that the problem is not simply that the number of humans has exploded in the past 100 years. For the very same reasons that we were able to dramatically reduce death rates (and thus unleash population growth) we have figured out how to dramatically increase our standard of living. What we haven't yet figured out is how even all of us currently alive can sustain our current level of living, much less continue to increase it.

Monday, July 9, 2018

Japan is Admitting More Immigrant Workers--Very Cautiously

Japan has entered its long-expected decline in population, and this seems finally to have awakened the idea that immigrants might be useful to the economy. A story in this week's Economist shows the tentative steps being taken.
Acceptance of foreign labour is gradually increasing in Japan, one of the world’s most homogenous countries, where only 2% of residents are foreigners, compared with 16% in France and 4% in South Korea. A poll conducted last year found opinion evenly split about whether Japan should admit more foreign workers, with 42% agreeing and 42% disagreeing. Some 60% of 18-29-year-olds, however, were in favour, double the share of over-70s.
Whatever Japanese think of them, foreign workers have become a fact of life, at least in cities. There are 1.3m of them, some 2% of the workforce—a record. Although visas that allow foreigners to settle in Japan are in theory available only to highly skilled workers for the most part, in practice less-skilled foreigners are admitted as students or trainees. The number of these has been rising fast. Almost a third of foreign workers are Chinese; Vietnamese and Nepalese are quickly growing in number.
Pressure from business lies behind the change in attitudes, both societal and official. Over the past 20 years the number of workers below 30 has shrunk by a quarter. In addition, the ageing population is creating jobs that few Japanese want at the wages on offer, most notably as carers. There are 60% more job vacancies than there are people looking for work. Industries such as agriculture, construction and nursing are increasingly dependent on foreigners. Some 8% of Sakura no Mori’s staff are foreign, as are 7% of workers at 7 Eleven, Japan’s biggest convenience-store chain. 
The government does not allow these immigrants to bring in family members and many are required to frequently renew their visas, presumably so that the government could send them home at any time. In most jobs they must also become fluent in Japanese which, unlike English, is not regularly learned in countries outside of Japan. It is likely that as the demographic pressure increases over the next few decades, the walls built up against immigration will have increasingly larger cracks in them.

Sunday, July 8, 2018

White Americans Are NOT Close to Minority Status

The idea that white Americans are on the verge of no longer being the majority in this country has taken root in the media and in the minds of an awful lot of people. This theme was once again pushed out to the public a couple of weeks ago by William Frey, a demographer at the Brookings Institution. I have known Bill for a long time and he is a very good demographer, but I hadn't blogged about his report because it troubled me--the data he was using--even though from the U.S. Census Bureau--just didn't quite square with my own impression of what is happening demographically. Thanks to my long-time friend, Rubén Rumbaut at UC, Irvine, for pointing me to an "open letter" from Dowell Myers at the University of Southern California in which Dowell summarizes his very important work on this problem:
Most of us are using the same analysis procedures this year as we did back in the 1990s, even though the Census Bureau totally overhauled their racial definitions and measurements in 2000. Now that we are nearing the end of the second decade of the 21st century, why would demographers still be using racial binaries (white vs. nonwhite) and mutually exclusive categories? At best, the public analysis I see reported only uses half of the available race data, the half that comes closest to the oldest idea of race in America, namely the “one drop” rule, that says any portion of nonwhite blood makes a person nonwhite, no matter what is their mother or father’s race or no matter how they truly identify.
Let me share exactly where I am coming from, because this was reported in two publications recently, one in the Annals of the American Academy of Political and Social Science, the other in the Washington Post (both co-authored with the political scientist Morris Levy). The Annals study, part of the May issue, devoted to “what Census data miss about American diversity,” reviews the changes in Census Bureau race projections since 2000 and tests the impacts of alternative versions of reporting on a randomized sample of white voters. It received favorable coverage in outlets ranging from Vox to
Many data consumers do not know that the Census Bureau actually tracks six definitions of white in their projections. There is a larger, inclusive count of each race and a smaller, more exclusive count, the latter having subtracted out all whites who also identify with another race (people such as Meghan Markle, who has a white father and black mother, and now is a member of the British royal family.)
The Census Bureau knows this problem of racial classification and handles it by reporting both exclusive and inclusive definitions of white. You can see the latest projections comparing these numbers out to 2060 here. [Go to Table 5]. It is up to the users to decide which version of white is best.
Thus, if we follow the Census Bureau's guidelines that Hispanic is an ethnicity, not a race, and if we accept the idea that many people of mixed race also include themselves as white, then we see that the Census Bureau estimated that in 2016, 79% of the U.S. population considered themselves to be white, compared to the non-Hispanic one-race only definition by which 61% were white. Then, using the very restricted definition of white, by 2045 whites would drop to slightly less than 50% of the population. However, by the inclusive definition of whites, by 2060 (the end date for the current Census Bureau projections) whites are still 74% of the population.

To put it another way--the melting pot is working and whites are not on the way out the door in this country. 

Friday, July 6, 2018

Explaining the U.S. Birth Dearth

A couple of months ago we heard the news that the U.S. birth rate was down yet again. My sense was that this was due largely to the increasing level of income and wealth inequality. The overall economy is doing OK--especially if you have money invested in the stock market--but the average person is not seeing their economic circumstances improve. The New York Times asked the survey research firm Morning Consult to see what it could find out and the results have been published today.
About a quarter of the respondents who had children or planned to said they had fewer or expected to have fewer than they wanted. The largest shares said they delayed or stopped having children because of concerns about having enough time or money.
The survey, one of the most comprehensive explorations of the reasons that adults are having fewer children [1,858 respondents — a nationally representative sample of men and women ages 20 to 45] tells a story that is partly about greater gender equality. Women have more agency over their lives, and many feel that motherhood has become more of a choice. But it’s also a story of economic insecurity. Young people have record student debt, many graduated in a recession and many can’t afford homes — all as parenthood has become more expensive. Women in particular pay an earnings penalty for having children.
The expense of child care was the top reason, as you can see in the graph below: 

This is entirely consistent with information in a blog post following up on the news about the drop in fertility. As I said then: "The policy point here is that if you want a higher birth rate, the government needs to subsidize child care for women, so that they can combine a career with parenthood. Men always have that option because society assumes that the child's mother will be the caregiver. But the evidence from Europe suggests that the government has to step in with child care to free women to be both workers and mothers. In essence, governments must accord women equal status with men on this score." The Morning Consult/NYTimes survey results are consistent with this idea.

Thursday, July 5, 2018

Could We Live Forever?

Thanks to Todd Gardner and others for pointing to a research article published this week in Science on the "Demography of Longevity Pioneers." The researchers, who included James Vaupel of the Max Planck Institute for Demographic Research in Germany and Ken Wachter of the UC, Berkeley Department of Demography, used data from older Italians. This had the advantage of choosing a population in which a fairly large number of people have survived to the oldest ages, and using data from a single data source, thus reducing the problem of comparing data collected in different ways. Their findings suggest that while death rates continue to climb up to age 105, after that they are constant, with about a 50% chance of survival each year beyond 105.

Nature picked up on the story and invited comments from people not involved in the study:
If there is a mortality plateau, then there is no limit to human longevity,” says Jean-Marie Robine, a demographer at the French Institute of Health and Medical Research in Montpellier, who was not involved in the study. That would mean that someone like Chiyo Miyako, the Japanese great-great-great-grandmother who, at 117, is the world’s oldest known person, could live for years to come — or even forever, at least hypothetically.
That would fit into the theory of longevity promoted by people like Elmo Keep, a science entrepreneur in the Silicon Valley, as I blogged about last year. On the other hand, not everyone thinks we should yet jump to these big conclusions:
Brandon Milholland, a co-author of the 2016 Nature paper, says that the evidence for a mortality plateau is “marginal”, as the study included fewer than 100 people who lived to 110 or beyond. Leonid Gavrilov, a longevity researcher at the University of Chicago in Illinois, notes that even small inaccuracies in the Italian longevity records could lead to a spurious conclusion.
Others say the conclusions of the study are biologically implausible. “You run into basic limitations imposed by body design,” says Jay Olshansky, a bio-demographer at the University of Illinois at Chicago, noting that cells that do not replicate, such as neurons, will continue to wither and die as a person ages, placing upper boundaries on humans' natural lifespan.
Only time will tell which conclusion is correct, of course. In the meantime, the number of old-old people is increasing in the world, so we'll have a consistently larger population from which to derive data. 

Tuesday, July 3, 2018

Demography of Aging Revisited

Yesterday I blogged about health disparities in the United States, referencing research by Jennifer Montez and Mark Hayward. The latter comes up again today, because he organized a workshop on the demography of aging for the National Academy of Science (NAS) from which the report has just been made available. Aging and health go together, of course. We wouldn't give nearly as much attention to aging as we do were it not for the fact that our health tends to deteriorate as we age. That is a personal problem, but one that our family and friends and, indeed, the entire society, winds up coping with. Our entire life course is very much influenced by health, as Mark Hayward makes clear in the introduction to the volume:
Changes in fertility, life expectancy, and population-age structure have had profound effects on the opportunities and constraints facing individuals, their families, and their communities. The older population has become more racially/ethnically diverse. Kin relationships have become more complex and fluid, and more people now approaching old age have been divorced and many have never been married. Population health now spans a web of health processes including biological risk, disability, cognition, and disease. The health and well-being of the older population are now seen as the consequences of long-run and cumulative effects of social, economic, and contextual factors over the entire life course.
The participants in the workshop, each with a chapter in this volume, are among the big names in the demography of aging, and this is a deliberate followup to a previous (1994) NAS report on the Demography of Aging. We know a lot more than we did then, thanks in part to the funding of research by the National Institute on Aging, and much of that learning tells us that the world is more complicated than we thought it was 24 years ago. This new volume dives into those complexities. Each chapter would be worthy of a blog post, but you should read it for yourself because if you are reading this you are aging, and you should know what lies ahead.

Monday, July 2, 2018

Health Disparities by State Mainly Reflect Different Levels of Education

I have blogged several times about the differences in health and life expectancy by state in the U.S. In a blog post about a year and half ago I highlighted the research of Professors Jennifer Montez of Syracuse University and Mark Hayward of UT, Austin. Their latest chapter in the story has just been posted on and it highlights the finding that the variability in health disparities around the U.S. are largely found among people at lower educational levels.
The researchers analysed extensive data on adults living in the US from two different surveys: the National Longitudinal Mortality Study and the American Community Survey. The researchers also collected data on the policies and characteristics of all US states. For example, they collected information on the states’ economic environment, income inequality, tobacco control policies, Medicaid coverage, and socio-political factors such as whether the state tends to vote for a Republican or Democratic presidential candidate, as well as characteristics of the states’ populations such as age, sex, race, ethnicity, educational levels. The data collected was then analysed in an attempt to gain a better understanding of the factors behind cross-state health disparities.
Drs Montez and Hayward found education level to be one of the strongest predictors of health and mortality rates among US residents. This is aligned with past research findings highlighting the impact of education on an individuals’ health. ‘In the United States, one of the best predictors of how healthy and long someone will live is their education level,’ says Dr Montez. ‘More years of schooling generally translate into better health and longer life.’
When I first saw this I jumped to the conclusion that it might be due to differing levels of access to health care. But the research suggests a more complicated relationship.
‘Education provides people with a large bucket of resources that they can use to create a healthy life,’ explains Dr Montez. ‘For example, people with more schooling tend to be employed in jobs they enjoy and that stimulate their minds, to marry and stay married, to have large and beneficial social networks, to feel in control of their life, and to engage in healthy behaviours like exercising and avoiding tobacco.’
The positive effects of education on health, therefore, go beyond those derived from generally higher salaries, such as access to more expensive medical services. While imparting field-specific knowledge or skills, education also teaches people how to navigate modern society and look after themselves as well as their families and friends. This tends to improve their health and wellbeing, while also opening a broader range of social and economic opportunities for these individuals.
This is important on-going research and we need to keep our eyes open for the next round of findings.