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:

Saturday, November 18, 2017

Dogs Are Good for Your Health!

Thanks to Todd Gardner and several others for pointing to a great study reported on by BBCNews showing that dogs are associated with better health among their owners than among people without dogs. The analysis is drawn from a large population-based longitudinal database in Sweden and the findings were just published in Scientific Reports.
We aimed to investigate the association of dog ownership with incident cardiovascular disease (CVD) and death in a register-based prospective nation-wide cohort (n = 3,432,153) with up to 12 years of follow-up. Self-reported health and lifestyle habits were available for 34,202 participants in the Swedish Twin Register.
Their overall conclusion is as follows:
[I]n a nationwide population based study with 12 years of follow-up, we show that dog ownership is associated with a lower risk of cardiovascular disease in single households and with a reduced risk of cardiovascular and all-cause death in the general population.
Taken together, we believe our longitudinal population-wide design provides the most robust evidence so far of a link between dog ownership and health outcomes, although bias from reverse causation, misclassification and confounding cannot be excluded.
Note that the authors are careful about the direction of causation. It may be that healthier people are generally more likely to have dogs, but even if that were true it doesn't negate the possibility that dogs can improve your health.

The one caveat that I would throw into the mix is that dog ownership is not always associated with loving the dogs. Our current German Shepherd was abandoned by its owner at a high-kill animal shelter here in Southern California when he was about one year old. Fortunately for Larry Bear (our name for him--his photo from just a few minutes ago is below) and for us, he was rescued by Coastal German Shepherd Rescue, and then he "rescued" us as we gave him his forever home. He's good for our health, and we're good for his health--it's a nice combination

Friday, November 17, 2017

Land Grabs and Hunger in Africa

A few days ago I posed the question: Can we keep feeding a growing population? My answer was don't bet on it, and other news this week speaks to some of the problems. Yesterday Reuters reported that the United Nations now estimates that the number of hungry people in Africa rose by 10% in 2016, pushing the overall number to 224 million. The explanation given was that the combination of conflict and climate change has made it harder to grow and distribute food in the sub-Saharan region. 

Keeping in mind that Africa has the fastest growing population in the world, what happens there has a huge impact on the global hunger picture. And one of the things happening in Africa is a land grab by wealthier countries who want to increase food productivity not necessarily for Africans, but rather as a source of food for themselves. Timothy Wise of the Small Planet Institute in Cambridge, Massachusetts (and also a senior researcher at the Global Development and Environment Institute at Tufts University) has been studying these issues for some time now and his group recently sent out this summary of some of the events he has been covering:
Tim was in Maputo October 23-24 for the Trinational People’s Conference on ProSAVANA, the controversial Mozambique-Brazil-Japan agricultural development project widely denounced by local farmers and communities as a land-grab. Fifty farmers took turns lecturing ProSAVANA director Antonio Limbau that they did not want large-scale foreign investments, they wanted support for their own food production. Tim has covered the conflict since 2014 (see previous articles here and here). This year he has also researched a controversial Chinese rice project; look for an in-depth report on the project soon.
While in Maputo, Tim presented at an African Union-sponsored three-day conference on “Climate Smart Agriculture,” the new catch-all term for agricultural practices that mitigate and adapt to climate change. He was part of an ActionAid-sponsored event on agro-ecology, where he laid out the evidence supporting a transition to soil-building agro-ecological practices, in contrast to the Green Revolution practices of monoculture fed by synthetic fertilizers. Colleagues from Zambia and Malawi presented case studies, and Tim offered observations of the successful project he’s seen in Marracuene, Mozambique. (See articles here and here.)
The point is that Africa needs its land to grow food for its rapidly growing population and it needs help (meaning investments, but not ones that are essentially confiscatory) to implement sustainable methods for increasing per acre productivity. The region's population growth will not be sustainable if Africans are routinely taken advantage of with respect to their agricultural land. 

Thursday, November 16, 2017

Weaponized Mosquitos May be Headed Your Way

Malaria continues to be one of the biggest killers of humans in the world, and since mosquito bites are the method by which the malaria parasite infects a human, controlling mosquitos is a big deal. And, of course, mosquitos help spread other deadly diseases besides malaria, including dengue fever and the Zika virus. Over the years I have often blogged about both mosquitos and malaria--most recently in April of this year on World Malaria Day, when I discussed a new malaria vaccine being introduced. Last week we had yet another development, as the U.S. Environmental Protection Agency approved the release of what are called "weaponized mosquitos" in 20 U.S. states.
The US Environmental Protection Agency has given its approval for MosquitoMate, a Kentucky-based biotechnology company, to release its bacteria-infected male mosquitoes in several parts of the United States.
The company’s lab-grown mosquitoes, which it calls ZAP males, are infected with the Wolbachia bacteria, naturally occurring in many insects, but not in Aedes aegypti, a vector for viruses such as yellow fever, dengue and Zika. When bacteria-infected males mate with uninfected females, the females produce eggs that don’t hatch. In addition, infected mosquitoes are less likely to spread disease.
Entomologist Stephen Dobson, CEO of MosquitoMate, told Quartz that the company could start selling the infected mosquitoes in the summer for use by municipal bodies and individual homeowners. The male mosquitoes don’t bite, which should make the release of these insects sound less alarming. 
The 20 approved states are California, Connecticut, Delaware, Illinois, Indiana, Kentucky, Massachusetts, Maine, Maryland, Missouri, New Hampshire, New Jersey, Nevada, New York, Ohio, Pennsylvania, Rhode Island, Tennessee, Vermont, and West Virginia, as well as Washington, DC. The permitted states include mostly those with similar weather conditions to Kentucky, New York, and California, states where the company earlier conducted trials.
While companies like MosquitoMate are trying to make mosquitos less dangerous, a report today from Nature News suggests that an old-fashioned anti-malaria strategy is being brought back in Africa:
In a sea of high-tech malaria fixes — everything from drug-delivery by drone to gene-edited mosquitoes — an old-fashioned approach is saving thousands of children in West Africa, according to studies presented this week at the American Society of Tropical Medicine and Hygiene (ASTMH) meeting in Baltimore, Maryland. 
The measure, called seasonal malaria chemoprevention, involves giving children a dose of antimalarial drugs once each month in the rainy season to prevent the disease in hard-hit regions. Researchers have previously demonstrated this strategy in large clinical trials but they had feared that their positive results wouldn’t be replicated in the messy, real world, because chemoprevention requires thousands of local health workers to deliver drugs to children in villages far from hospitals, pharmacies and paved roads.
I personally have always taken anti-malaria drugs with me to Africa, and the idea that these drugs could help save children from malaria through this selective dosage strategy is very intriguing. We are still at that stage where we have employ all of the "weapons" we can. 

Wednesday, November 15, 2017

Migration Morphs Into Slavery in Libya--UPDATED

CNN has put together a very troubling report on the way in which human migration from Sub-Saharan Africa to Europe by way of Libya has morphed into not just human trafficking, but into real slavery.
Each year, tens of thousands of people pour across Libya's borders. They're refugees fleeing conflict or economic migrants in search of better opportunities in Europe. Most have sold everything they own to finance the journey through Libya to the coast and the gateway to the Mediterranean.
But a recent clampdown by the Libyan coastguard means fewer boats are making it out to sea, leaving the smugglers with a backlog of would-be passengers on their hands. So the smugglers become masters, the migrants and refugees become slaves.
As the route through north Africa becomes increasingly fraught, many migrants have relinquished their dreams of ever reaching European shores. This year, more than 8,800 individuals have opted to voluntarily return home on repatriation flights organized by the IOM.
This turn of events is probably not a surprise to the researchers at the "Human Costs of Border Control" project at the University of Amsterdam. 
On the basis of globalization theories, as well as on the basis of developments in European migration policies, we hypothesize that since 1990 migration law has witnessed a shift from migration control (reactive, focus on concrete individuals) to migration management (pro-active, focus on potential migrant populations). A second hypothesis is that the increased number of ‘irregular’ migrants dying on their way to Europe is an unintended side-effect of this shift. Thirdly, we propose that as a consequence of the shift to border management, the human rights protection previously available regarding migrant fatalities under border control, has become considerably less effective.
After ten years of work, they have just wrapped up their research, the results of which remind us that migration policies are actually matters of life and death in their consequences.

UPDATE: The Migration Policy Institute in Washington, DC has just posted a very interesting review of the changing migration policies between Spain and Morocco and between Italy and Tunisia. Reading this helps to illustrate how complicated the policy issues are with respect to migration from South to North.

Tuesday, November 14, 2017

Can We Keep Feeding a Growing Population? Don't Bet on it

In 2011, Professor David Lam of the University of Michigan was the President of the Population Association of America and in his presidential address at the Annual Meeting that year in Washington, DC, he predicted that there should be plenty of food to go around even as the world added another 4 billion people. [Like all presidential addresses, this was published later that year in the journal Demography.] Professor Lam updated some of these ideas in a recent article in the online news magazine of the International Union for the Scientific Study of Population (IUSSP). This was followed yesterday by a sort of rebuttal of that optimism from Richard Grossman, a retired gynecologist and public health physician.
As a demographer, it is appropriate that Lam should focus on humans. However, I fear that he has largely ignored the environment in which we live when he wrote this essay. I have difficulty accepting his statement: “An important source of optimism about the world’s ability to support an additional 4 billion people is the success in supporting the previous 4 billion.” My concern is that the past 4 billion have degraded natural world upon which we depend, and that this degradation will make the world much less welcoming to the next 4 billion.
If you've read Chapter 11 of my Population text you will know that I too worry about this same issue, and you won't find anything really new or exciting in what Grossman is saying. Rather, it is very troubling. Grossman also reminds us that Lam's optimism back in 2011 was subsequently challenged by Professor Stan Becker of Johns Hopkins University: 
In 2013, Professor Stan Becker challenged Professor Lam after his presidential address at the Population Association of America in 2011 in which he forecast “I expect that it [the world] will have improved in many ways, including lower poverty, higher levels of education, and plenty of food to go around” (Lam 2011:1259). Drs. Lam and Becker have a wager on food prices (collected by FAO) over the period 2001-10 to 2011-2020, with Lam predicting they will go down and Becker predicting they will go up. Half of the period of interest has passed (2011 to 2016), and prices have risen, by about 51% globally (Table 1).
And, of course, prices are going up because we have essentially used up all the available good farmland, we have to apply new and expensive technologies to get more food out of each acre of land, and we waste a lot of land and food on animals that are killed for humans to eat. 

Sunday, November 12, 2017

South Koreans Push for the Right to Choose

For several decades abortion has been a legal and important method of fertility control for women in China and Japan. Not so in South Korea, where abortion has been outlawed since 1953 except for cases of rape, severe health threat to the mother, or a severe fetal defect. This week's Economist reports on a new push in South Korea to legalize abortion. The interesting thing about this effort is that it became necessary because a few years ago a concerted effort emerged to enforce the restrictions on abortion.
[F]or a long time governments turned a blind eye to it, viewing it as simply another form of birth control. Doctors readily provided it. Many people did not even know that it was illegal to have one. To this day the government estimates that around 170,000 pregnancies are aborted every year.
But in 2010 a group called Pro-Life Doctors started reporting hospitals offering abortions to the police. Wealthy and politically influential religious groups began campaigning against the practice too. The president at the time, Lee Myung-bak, a devout Christian, vowed to prevent illegal abortions. He created a task force to ensure the law was enforced, presenting the move as a way to lift falling fertility rates. It did not work: in 2016 there were only 406,000 live births, the lowest number on record. It did lift prices though: during Mr Lee’s term, the cost of a furtive abortion reportedly rose tenfold.
Keep in mind that a relatively rapid drop in fertility has been one of the keys to South Korea's economic success. At the same time, the birth rate is only slightly below replacement level, and is higher than in either China or Japan. Thus, it is a bit of a stretch to suggest that penalizing abortions will make a huge difference in the birth rate. This is largely a humanitarian reproductive rights issue.
A recent survey found that only 36% of people want to keep abortion as a criminal offence, down from 53% in 2010. The constitutional court is due to rule soon on a challenge to the abortion law, on the grounds that it is an unwarranted infringement of women’s personal liberty. In 2012 the court voted narrowly to uphold it, but several more liberal judges have joined since then.
To the extent that religion might play a role in the abortion debate, it is interesting to note that South Korea is a country in which there is no religious majority. A Pew Research report shows that people with no religious affiliation are the largest single group (46%), followed by Christians (29%) and Buddhists (23%). The current President, Moon Jae-In is a Roman Catholic. 

Friday, November 10, 2017

How Well Can We Predict Our Own Survivability?

Having recently had my own brush with death, I was fascinated by one of the articles in the latest issue of the Vienna Yearbook of Population Research (Volume 14--2106) published by the Vienna Institute of Demography. Well, actually, they are all good articles, but the one by Alberto Palloni and Beatriz Novak caught my eye for two reasons: (1) Professor Palloni is a Past President of the Population Association of America (click here for an interview with him), and (2) we humans tend to be very interested in our potential ability to evaluate our own likely age at death.

In their research, Palloni and Novak compared people's own subjective responses about their probability of surviving to a particular age, with life table probabilities based on calculations from death certificate analysis at the national level. Their source of data for people's subjective probabilities was a set of questions asked in the Health and Retirement Study (HRS), funded over many years by the National Institutes of Health.
The HRS is a longitudinal survey designed to gather information on individuals in the U.S. from pre-retirement into retirement. The first wave’s (1992) target population included individuals born between 1931 and 1941 who were living in households, and the spouses or partners of these individuals, regardless of their ages. Out of the 15,497 individuals who were eligible to be interviewed in 1992, 12,654 respondents were actually interviewed. Since then, the individuals in this initial cohort have been re-interviewed every two years. The entire survey consists of five birth cohorts who have been incorporated into the study over time. In the present study, we examine data from the first, fourth, and fifth HRS cohorts.
Here's what they found:
We show that the subjective probabilities are remarkably close to the results of actual life tables constructed from observed data, that whites underestimate their survival chances more than blacks, that women underestimate their survival chances more than men, and that the subjective underestimation of conditional survival increases with age in all population subgroups. We find significant differences in the survival outlooks of the original HRS cohort and a more recent HRS cohort (1992 versus 2004). These differences persist after introducing suitable controls. The observed mortality differentials between smokers and non-smokers, obese and non-obese individuals, and high-education and low-education groups are quite close to those of these subgroups’ subjective survival expectations. Finally, we find large updating effects that result from recent health shocks on subjective expectations.
As the authors note, this is really an extension of the literature showing that self-rated health generally comes very close to what physicians would say about you in a physical exam. We tend to know ourselves pretty well, and tend to monitor our likely chances of survival in a reasonably realistic way. 

Thursday, November 9, 2017

Will People in Poland Start Breeding Like Rabbits?

Thanks to Justin Stoler for the link to a BBC video on a new attempt by the Polish government to get people to raise the birth rate--encouraging them to "breed like rabbits". The video also reminds us of other attempts at this, including the Danish advertisement aimed at getting young adults to think romantically and not just have sex, but to have kids.

I'm guessing that this will not be an easy sell in Poland. The country's total fertility rate dropped down to replacement level way back in 1990, and it has slowly slipped since then down to almost 1.3. The slowness of the drop has been beneficial in the sense that it has not sent huge shocks through the age structure. Poland is aging, right along with the rest of Europe, but the population aged 20-64 (working ages) has been pretty steady at about 65% of the population. At the moment there are just about as many people under 20 as there are 65 and older. The total population size peaked in 2000 at just above 38 million, and it is still above 38 million, so there is nothing to suggest pushing the panic button.

It seems likely that this attempt to raise the birth rate is meant as a pushback against complaints by the EU that Poland has refused to accept any refugees from the Middle East. The Telegraph noted a couple of months ago that the new right-wing government in Poland is not interested in accepting refugees. Since refugees tend to be young adults--often with their children--they could be seen as an alternative to native Poles raising their birth rate, but that is clearly not currently a popular option in Poland. (And, by the way, the Danes are not interested in new refugees, either...)

Monday, November 6, 2017

Guns are a Public Health Risk in the U.S.--Redux

It is painful to note that it was scarcely a month ago that I blogged about the fact that guns are a public health problem in the United States. That was in reference to the mass shooting in Las Vegas, but Sunday's massacre at a church in Sutherland Spring, Texas, has raised that issue again. Nicholas Kristof has a very good Op-Ed in today's NYTimes laying out the case--yet again. His approach is one that makes sense, and could (please!) be politically palatable both to gun-owners and non-owners--following what we did for automobiles by making them safer.
Gun enthusiasts often protest: Cars kill about as many people as guns, and we don’t ban them! No, but automobiles are actually a model for the public health approach I’m suggesting.

We don’t ban cars, but we work hard to regulate them – and limit access to them – so as to reduce the death toll they cause. This has been spectacularly successful, reducing the death rate per 100 million miles driven by 95 percent since 1921.

Take a look at the history of motor vehicle safety since World War II:
It took a long time to make cars safer, but we've done a good job of this. The sooner we start on making guns safer, the better off we will all be.
Some of you will protest, as President Trump did, that it’s too soon to talk about guns, or that it is disrespectful to the dead to use such a tragedy to score political points. Yet more Americans have died from gun violence, including suicides, since 1970 (about 1.4 million) than in all the wars in American history going back to the Revolutionary War (about 1.3 million). And it’s not just gang-members: In a typical year, more pre-schoolers are shot dead in America (about 75) than police officers are.

Yes, making America safer will be hard: There are no perfect solutions. The Second Amendment is one constraint, and so is our polarized political system and the power of the gun lobby. It’s unclear how effective some of my suggestions will be, and in any case this will be a long, uncertain, uphill process.
We cannot sit back passively and wait for things to happen. People need to talk to their members of Congress, non-profit organizations need to get involved, and the gun manufacturers need to be brought into the dialogue, just as auto manufacturers were.