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:

Thursday, December 27, 2018

U.S. Population Growth Hits an 80-Year Low

Thanks to Rubén Rumbaut for pointing me to a nice summary of U.S. demographic trends by Brookings Institution demographer William Frey. The U.S. Census Bureau recently came out with its year-end summary of what happened between July 1, 2017 and July 1, 2018, and Bill gets right to the point--we're getting older and slowing down. Yes, I mean all of us, but this applies generally to the U.S. population.
Their data show that the national rate of population growth is at its lowest since 1937, a result of declines in the number of births, gains in the number of deaths, and that the nation’s under age 18 population has declined since the 2010 census. This is on the heels of recently released data showing geographic mobility within the U.S. is at a historic low. And while some states—particularly in the Mountain West—are growing rapidly, nearly a fifth of all states displayed absolute population losses over the past two years.
Here's what it looks like graphically:

As the baby boomers move into the older ages, the number of deaths is increasing, and since younger women are delaying having babies (and may have fewer than previous generations), and fewer immigrants are coming into the country, we are growing very slowly. This is probably good for the environment, but it introduces a lot of potentially unwelcome changes that we may all be coping with for the rest of our lives.
This week’s release of census estimates appears to put an exclamation point on what we should be preparing for as the country ages and grows less rapidly from natural increase. The latest national growth rate of 0.62 percent is noticeably below what we have experienced in decades prior. While it is still far higher than in countries like Germany, Italy, and Japan, it means that policymakers must place increased attention on caring for a larger and more dependent aging population, and dealing with the realities of a slower-growing labor force. In particular, it requires a more serious discussion of U.S. immigration policy because of the future contributions that immigrants will make to growing America’s society and economy.
I couldn't agree more. Immigration policy should be the #1 topic under discussion by Congress when they reconvene--right after they get the budget back on track and continue the funding of the Census Bureau!

Wednesday, December 26, 2018

Why Are More Boys Born Than Girls?

Thanks to both Justin Stoler and Debbie Fugate for linking me to a Christmas Day story from BBC News on the sex ratio at birth. I'm not sure if there was any significance to its publication yesterday, but the headline is a question: Why are more boys than girls born every single year?  This happens all over the world and has been going on for as long as people have been collecting such information. It is well accepted that the "normal" sex ratio at birth is 105 boys born for every 100 girls born. Why?The short answer is that we really don't know for sure. The first theory discussed in the article is the evolutionary theory, although here we can only describe what we see, without knowing for sure why the pattern has evolved as it has.

The article doesn't really articulate the evolutionary theory very well, so let me quote from the 12th edition of my text, first from Chapter 5 (p. 158):
The most basic health difference between males and females is that males have higher death rates than females from conception to the very oldest ages. Seemingly to compensate for this, more males are conceived than females. Fetal mortality is higher for boys than girls, but there are still typically more males born than females. Infant and childhood mortality rates are higher for males, with a roughly equal number of males and females being reached, quite conveniently from an evolutionary perspective, in the prime reproductive ages of the late teens and early twenties. After that, the only bump in the road for females compared to males is high maternal mortality, and by the older ages we can almost always expect to find more women than men.
And then from Chapter 8 (p. 305):
Despite the concern about the high and even increasing sex ratio in some countries, there is still the underlying question of why the “normal” sex ratio is not simply 100. The answer is that no one really knows (Clarke 2000). This is perhaps a biological adaptation to compensate partially for higher male death rates (or vice versa, since we also are not sure why death rates are higher for males, as I mentioned in Chapter 5). In fact, data on miscarriages and fetal deaths suggest that more males are conceived than females, and that death rates are higher for males from the very moment of conception. Thus, some of the variability in the sex ratio at birth could be due to differences in fetal mortality. But we aren’t sure why those differences exist, either. Research done as part of the human genome project suggests a role played by the X chromosome, but that is still just a guess (Gunter 2005).
That pretty well sums up what we know. The patterns are clear--the reasons for those patterns are not.

Wednesday, December 19, 2018

Set it and Forget it: Reducing Unwanted Pregnancy

Thanks to one of my readers, Du Elium Kayali Araujo, for the link to a story closely related to my recent post on the dangers of getting pregnancy in the United States. Yesterday the NYTimes Upshot writer Margot Sanger-Katz posted a story about how better contraception could be a key to reducing poverty. If you've followed my blog over time, you know that in my opinion this is not speculative ("could") but is definitive ("will").
Unplanned pregnancies remain astoundingly common. According to the Guttmacher Institute, they represented 45 percent of all pregnancies in the United States in 2011. The majority of abortions, which numbered more than 900,000 in 2014, are in response to unplanned pregnancy, and there are signs that the new program has pushed down Delaware’s abortion rate.
The new program referenced in the article is in Delaware and is a collaboration with a national organization called Upstream. The goal is to reduce unplanned pregnancies by providing women with a one-stop shop for contraception, with a particular emphasis on long-acting reversible contraceptives (LARC).
Without a LARC, preventing pregnancy means taking steps like filling prescriptions and remembering to take a pill every day. With one, a woman won’t become pregnant until she takes the step of removing it.

“Set it and forget it,” said Venus Jones, an Upstream trainer. “We call it the Crock-Pot method.”
The program has the very positive impact of reducing abortions, and it has the strong potential to improve the lives of women and their children:
Children whose births are unplanned are likelier to have health complications, to be born into poverty, to stop their education sooner and to earn less. Mothers of unplanned children tend to give birth when they are younger, leave school earlier and earn less when older.
Isabel Sawhill, a senior fellow at the Brookings Institution, has measured the wide gulfs in outcomes between young women with unintended children and those with planned pregnancies later on. She has written extensively in support of expanded LARC access.
“It’s very expensive and very hard to reduce poverty,” Ms. Sawhill said. “Reducing unplanned births is easy by comparison.”
I first made reference to Sawhill's book Generation Unbound more than four years ago, and I've commented on it in several other blog posts since then. If you haven't read her book, you should do so. 

Monday, December 17, 2018

The Dangers of Getting Pregnant in the U.S.

Last month I blogged about new data from the U.S. Centers for Disease Control & Prevention showing that pregnancy related deaths in the U.S. are higher than in any other rich country. A story appearing in the January 2019 issue of the National Geographic explores the problem in an up close and personal way. The title and subtitle summarize the situation very nicely:

Why giving birth in the U.S. is surprisingly deadly 

Black mothers are particularly at risk.

Better basic care could help.

In the United States the problem is marked by two particularly alarming statistics: African-American women are about three times as likely to die of pregnancy-related causes as white women, and more than 60 percent of maternal deaths are preventable, according to the Centers for Disease Control and Prevention (CDC).
“We have higher maternal mortality than much of the rest of the developed world; we are capable of doing the best in the world,” says William Callaghan, the CDC’s chief of maternal and infant health. The CDC defines a pregnancy-related death as a woman who dies while pregnant or within one year of the end of her pregnancy.
“When deaths are reviewed and we see what the contributing factors were, there are so many instances where communication was not carried out correctly, where people didn’t recognize urgency, or when the patient wasn’t listened to, or the delay in reaction.”
Why are death rates higher among African American women? Here is one possibility:
Valerie Montgomery Rice, president and dean of the Morehouse School of Medicine in Atlanta, Georgia, believes that not only do bias and racism build up to affect the health of black women over time, but that stress from racism and poverty may have adverse effects as early as in utero or soon after a baby is born.
This is consistent with the effect of Trump administration attitudes towards immigrants on the health of Latinas and their babies, as I noted not long ago

And, of course, I have often noted that the former slave states of the south have the highest death rates in the country, and these are areas with high proportions of African Americans. Where you live still matters when it comes to your health.

Saturday, December 15, 2018

Visualizing the Changing Urban Population

I happen to really like 3D maps. I think that they are terrific visualization tools, and so I was very pleased when Todd Gardner pointed us to a new set of such maps created by the Human Terrain project at Pudding, and yesterday summarized by Nick Routley at the Visual Capitalist. Here, for example, is the map for Dallas, Texas, showing the change in population at the local level between 1990 and 2015:

The green bars represent population increase over time, showing that the northern suburbs are where the metro area has. been growing. This helped explain to me why there is now a Frisco Bowl, where my San Diego State Aztecs will play the Ohio Bobcats next week. I've been in and out of Dallas many times over the years, but had not paid attention to those northern suburbs until I saw this map. And, while you might think that a 3D map should show a hole where there is population decline, these maps put the negative growth in red instead of green. Thus, you can see that the southern suburbs of Dallas have experienced a loss of population since 1990. My late father-in-law was born in Seagoville, just off the map below Mesquite, and I don't think he would be surprised at that demographic change.

Wednesday, December 12, 2018

Mexico is Now Dealing With the US Undocumented Immigration Issue--UPDATED

With any luck you saw the Pew Research report a couple of weeks ago in which they estimate that the number of undocumented immigrants in the U.S. has been declining. This is due mainly to the fact that the migration of undocumented Mexicans into the U.S. has dropped precipitously over the last decade as the birth rate in Mexico has fallen and the economy has grown. The “demographic fit” between the U.S. and Mexico has pretty much ended, but that doesn’t mean the end of undocumented immigration.

My thanks to Professor Rubén Rumbaut for pointing me to an article from the Center for American Progress highlighting the increasingly important role that Mexico is playing in coping with migrants. In the first place, they have been coping with a large number of Mexican migrants who have been deported from the U.S. back to Mexico. The Pew report reminds us that the number of deportations of people back to Mexico increased dramatically first under the Bush administration and then particularly under the Obama administration. Indeed, I noted a few years ago that Obama was being called the “deporter-in-chief.” This has not been easy for Mexico to deal with, as these people are typically dumped across the border with few resources of their own. The Mexican government’s programs are under-funded although at least some of the slack has been taken up by non-profit organizations.

The second and more dramatic issue is the role being played by Mexico as an increasing number of migrants leave the “northern triangle” countries of Guatemala, El Salvador, and Honduras, to seek refuge in the north from the horrific conditions they face in their respective countries.

Mexico is facing new challenges as millions of Mexican migrants return from the United States and Central Americans seek asylum and safe passage through the country. Historically, Mexico has been a predominantly immigrant-sending country. Political unrest and violence in Central America, heavy-handed immigration enforcement in the United States, and increased development in Mexico has made Mexico a country of destination, return, and transit. Each of these roles demands a unique, humane, and thorough policy response.
My own view is that the United States needs to provide governmental support to Mexico to deal with this situation, while at the same time encouraging public-private investments in Mexico and the northern triangle countries to improve the quality of life and thereby reduce the pressures people face to get out of there and head north. Like everything associated with migration, this won’t be easy, but the longer we wait, the harder it will be.

UPDATE: Today the Washington Post reported that the U.S. will provide more aid to Mexico and Central American governments in renewed attempts to cut down the migration from Central America.
The United States announced a total contribution of $10.6 billion, most of which will be allocated from existing aid programs. Around $4.5 billion of that sum comes from new loans, loan guarantees and other private-sector support that could become available through the Overseas Private Investment Corporation (OPIC).
The Mexican government said it would contribute $25 billion to development in southern Mexico over five years, which López Obrador has suggested could serve as a source of employment to Central Americans who are granted work visas. 
López Obrador “has to take advantage of this opportunity, this honeymoon with Trump and Mexico,” said Rafael Fernández de Castro, a former senior Mexican foreign affairs official and now director of the Center for U.S.-Mexican Studies at the University of California at San Diego.
The WP thinks this may be mostly symbolic, but at least it is a step in the right direction. 

Monday, December 10, 2018

UN Approves Migration Pact

The United Nations has been working on a global migration pact for quite a while now, and today there were 165 countries who signed on to it. The United States and several other countries chose not to participate, "citing concerns about migrant flows and national sovereignty" as the New York Times reported. 
The text of the accord was approved in July by every member of the United Nations except the United States. But it has since gotten caught up in a nationalist movement in Europe that has centered on the issue of immigration and prompted around a dozen countries to reject the compact outright, or to pull back from endorsing it in Morocco.
The United Nations has insisted all along that this pact was not a mandate for rich countries to take in poor migrants. Rather, it was an acknowledgement that migration is a fact of life, and every country should make good decisions about how to cope with it.
The Global Compact for Safe, Orderly and Regular Migration, a 34-page document, asserts that “no state can address migration alone” and outlines 23 objectives. They include the collection of better data on the movement of migrants, the strengthening of legal paths to migration, efforts to combat human trafficking and cooperation to ease the safe return of migrants to their countries of origin.
Most migration is not from “south to north” but between developing countries, he said, seeking to dispel other falsehoods and noting that there were more African migrants in other African countries than there are in Europe.
Moreover, migrants provide a boost to the economies of their host countries as well as to their countries of origin, he said. Migrants spend 85 percent of their earnings in the countries where they work. They send the remaining 15 percent home in remittances, providing vital lifelines to developing countries that add up to three times the value of official development assistance from richer nations.
The fact that most migration is not "south to north" is important to remember, but of course that does not assuage people who want to raise alarms about the south to north migration that they feel affects them. And, to be sure, part of the global compact is an attempt to address xenophobia and the integration of migrants into societies. These are not easy to do and almost always take more time than people think they should. 

Friday, December 7, 2018

Age at First Birth is Steadily Rising

A couple of weeks ago, I mentioned that data from the Current Population Survey show that the age at marriage in the United States has been been steadily rising. This week a closely related analysis shows that the age at first birth has also been going up. Indeed, between 1970 and 2017 it went from 21.4 years to 26.8 years. These data were put together by Karen Guzzo and Krista Payne at Bowling Green State University's National Center for Family & Marriage Research. 

The results are especially interesting because they show that there are clear geographic differences in the delay in first birth. Thus, while the age at first birth has been going up everywhere, it is going up much more in some states than in others, as you can see in the map below.

The increases have been greatest along the west coast and in the northeast. Two southern states--Arkansas and Mississippi--share the honors of having the lowest age at first birth in both 1970 and 2017. By contrast, Massachusetts, Connecticut, and New Jersey were all consistently at the older ages with respect to first births in both 1970 and 2017. However, in 1970 the difference between the youngest and oldest was considerably less (22.5 - 20.2 = 2.3) than it was in 2017 (29.7 - 24.1 = 5.6). 

These results suggest yet another way in which the population of the United States is growing more diverse, since the differences in delaying the first birth are both a cause and a consequence of a wide array of changes that are taking place all over the country. 

Wednesday, December 5, 2018

It's Still 1986 When it Comes to Immigration Reform

If you watched today's memorial service for President George H.W. Bush, you had to have laughed and cried a lot, especially at the stories told by Alan Simpson, a former Senator from Wyoming and a good friend of the late President Bush. He was essentially ambushed politically after co-sponsoring the Simpson-Mazzoli Immigration Reform and Control Act of 1986. The Daily Beast talked to him about it today:
Designed to stem the tide of illegal immigration, it was passed by a Democratic House and Republican Senate and signed into law by President Reagan. Former Wyoming Republican Senator Alan Simpson co-sponsored the legislation together with Democratic Rep. Romano Mazzoli from Kentucky. Neither lawmaker seemed an especially natural fit for an issue with little direct impact on their constituents, but as chairs of their respective immigration subcommittees, they were thrust together into a position of leadership.
It was a model for bipartisan congressional problem solving, but the legislation that resulted is widely viewed as a failure—part of the problem, not the solution. It built on a three-legged approach—controlling the borders, increasing the number of visas for agricultural workers, and offering “earned legalization” to immigrants who had illegally entered the country before 1982. Instead of slowing the flow of people across the border, illegal immigration accelerated, and the politics of reform stretched to a breaking point. The cross-party alliances that had worked so well in the ‘80s crashed and burned as an effort launched by President Bush together with Senators Ted Kennedy and John McCain in 2006 imploded in the face of grassroots opposition.
Why didn't it work? Simpson argues that the "guts" were taken out of the bill before it could be passed. The visas for agricultural workers--essentially a guest-worker program to replace the earlier Bracero program--were viewed as being dangerously close to a national ID card, to which people on both the political right and left objected. Without this in the bill, employers couldn't know who they were hiring and could thus be accused of hiring undocumented immigrants.

Three decades later, Simpson sums up where we currently stand with undocumented immigrants:
“They (critics of reform) think these people are expendable,” says Simpson. “If you think America is good to them, you’re crazy as hell. They’re used and exploited and they work for four bucks an hour. It’s a pretty sick country that uses human beings like this. They sit on corners waiting for some guy to come by to get the gardening done at his estate. It’s a sad situation; it’s not pleasant to watch.”
Also not pleasant, as I noted yesterday, is that living in fear is not good for women and their babies, either. 

Tuesday, December 4, 2018

Laws Threatening Immigrants Can Affect Birth Outcomes

My thanks to Professor Rubén Rumbaut for linking me to a paper just accepted for publication (and now available online) in the American Journal of Epidemiology. The paper is titled "Restrictive Immigration Law and Birth Outcomes of Immigrant Women," and its authors--Florencia Torche and Catherine Sirois--are at Stanford University. The paper examines what happened to pregnant women in Arizona when that state passed a very aggressive anti-immigration law (SB 1070) back in 2010. The short answer is that the probability increased that an undocumented woman would give birth to a low-weight baby.
Prenatal exposure to the bill resulted in lower birthweight among Latina immigrant women, but not among US-born white, black, or Latina women. The decline in birthweight resulted from exposure to the bill being signed into law, rather than from its (limited) implementation. The findings indicate that the threat of a punitive law, even in the absence of implementation, can have a harmful effect on the birth outcomes of the next generation.
The low birthweight data are especially noteworthy because many of us have over time demonstrated that Hispanic women in the United States tend to have better outcomes than non-Hispanic Whites. To be sure, Professor Rumbaut and I published research on this more than 20 years ago:Rubén G. Rumbaut and John R. Weeks, "Unraveling a Public Health Enigma: Why do Immigrants Experience Superior Perinatal Health Outcomes?" Research in the Sociology of Health Care, 13(B): 337-391, 1996. So, when the results show that birth outcomes are worse, not better, we know that something is going on. This is a case where correlation is apt to be showing causation.

As the authors point out, these children are now U.S. citizens and will be tomorrow's workers and voters. It was reckless and pointless to have harmed their health during pregnancy. These are among the many, many reasons why Congress needs to get together and craft a genuine immigration reform bill.

Sunday, December 2, 2018

Is 60 the New 50? Chronological vs. Biological Aging

CNN posted a very relevant demographic article a couple of days ago comparing biological aging with chronological aging. The focus was on the research of Morgan Levine at Yale Medical School:
Essentially, everyone has two ages: a chronological age, how old the calendar says you are, and a phenotypic or biological age, basically the age at which your body functions as it compares to average fitness or health levels.
People with a biological age lower than their chronological age have a lower mortality risk, while those aging older from a biological standpoint have a higher mortality risk and are potentially more prone to developing the diseases associated with the higher age range. 
But perhaps what's most important here -- unlike results from genetic testing -- is that these are measures that can be changed. Doctors can take this information and empower patients to make changes to lifestyle, diet, exercise and sleep habits, and hopefully take steps to lower the risk and improve their biological age.
This is very important and useful work, since very few of us want to experience a longer life expectancy that involves many more years of disability. Indeed, researchers at the Institute of Health Metrics and Evaluation at the University of Washington have given us Disability-Adjusted Life Years (DALYs) that attempt to take into account the difference between biological and chronological aging (see Chapter 5 of my text for a discussion). The article didn't mention that. 

However, the most important omission in the CNN article was not mentioning that Dr. Levine's work is being done in collaboration with Dr. Eileen Crimmins and her colleagues at the University of Southern California. Earlier this year the two of them published an article in the journal Demography titled "Is 60 the New 50? Examining Changes in Biological Age Over the Past Two Decades." And a clue to how important this is to demographers is the fact that Dr. Crimmins has just been elected President-Elect of the Population Association of America.