More Sleep + Less Sugary Soda = Better Heath

OK, with any luck you already know these things, but it always helps to have new research come along to remind us of these truths. The Nation's Health (from the American Public Health Association) summarizes a study published recently in the Proceedings of the National Academy of Science. 

We show that more than one-half of racial differences in cardiometabolic risk can be explained by sleep patterns—namely, less total sleep and lower sleep efficiency among African American than European American adults. Sleep is a malleable health behavior that is linked with characteristics of the social and physical environment and could be an effective target in national efforts to reduce racial health disparities.

Differences in sleep patterns may be attributed to increased exposure to social stresses, the study showed. Stressors associated with socio-economic status and systemic discrimination can lead to low sleep efficiency.

Although the study compared racial/ethnic groups, the lesson is true for everyone--better sleep is associated with better health. You can find out more about this by thumbing through issues of the Journal of Sleep Research--with luck it won't put you to sleep... 

Sugary sodas have been under attack for a long time and the evidence continues to mount that they push your weight up, and that is bad for your health in a variety of ways. The latest research comes from the American Journal of Public Health and uses data from a population of teachers in Mexico.

We followed 11 218 women from the Mexican Teachers’ Cohort from 2006 to 2008. Dietary data were collected using a semiquantitative food frequency questionnaire. Weight was self-reported, and waist circumference was self-measured. We used linear regression to evaluate changes in sugar-sweetened and sugar-free soda consumption in relation to changes in weight and waist circumference, adjusting for lifestyle and other dietary factors.

Decreasing consumption of sugar-sweetened soda was associated with less weight gain, and increasing consumption of sugar-sweetened soda had an opposite association. These results were similar when waist circumference was used as a measure of adiposity. The impact of changes in sugar-sweetened soda intake on weight appeared to be stronger among women who were overweight or obese at baseline relative to women who were of normal weight. Changes in sugar-free soda consumption were not associated with weight change.

Thus, if the consumption of sugary sodas increased over a two-year period, so did a person's weight. Conversely, less sugary soda was associated with a weight loss. The results were not huge, but this was only a two-year timeframe. And the fact that sugar-free sodas had no effect lends credibility to the findings.

So, drink less sugary soda, get more sleep, and, by the way, don't forget to be vaccinated against the flu. 

Chinese Government Doesn't Want Us to Know About the Low Birth Rate

A recent story in the South China Morning Post notes that the latest Statistical Yearbook from China omits mention of the birth rate. Very suspicious!

China’s National Bureau of Statistics has been publishing the data on the “age-specific fertility rate of child­bearing women” – the measure of how many children were born to different age groups – annually since 2004.

But in the 2017, China’s statistics yearbook, which sets out the data from the previous 12 months, the bureau said it had decided to remove these figures, which help to calculate the country’s overall fertility ratio [the total fertility rate, as we would call it].

Almost three years ago, as the one-child policy was being lifted in China, I commented on the fact that demographers did not expect a rise in the birth rate, whereas the Chinese government did. Not surprisingly, the demographers appear to continue to be right.

The statistics agency’s number, which indicated a fertility ratio of 1.05 in 2015, ran counter to an estimated fertility rate of 1.6 from the National Heath and Family Planning Commission, the body that is responsible for China’s family planning policy and ruthlessly implemented the country’s one-child policy for decades. 

While the statistics agency did not explain why it stopped publishing the data, demographers said it underscored the problems with China’s official population figures.

Liang Zhongtang, a demographer who sat on the state family planning commission in the 1980s, said China’s fertility rate had failed to show any meaningful increase after the country officially rolled out a universal two-child policy in 2016, adding that could be one reason for the non-disclosure. “A gap between what the government actually got and what they had expected may persuade them to stop releasing the data,” Liang said.

If the birth rate really is still close to one child per woman, as we expect it really is, the consequences for China's age transition are clear: the aging population will continue to grow more quickly than the younger labor force, and this will create continual strains on the Chinese economy. It is not clear whether or not this feeds into the new "Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era" that is now enshrined in the communist party's constitution. What we do know from the South China Morning Post story is that family planning wasn't mentioned by Xi during the recent communist party gathering. "Instead, Xi used the much milder term “population policy” and stressed that China must “enhance strategic research” into its demographics."

Demographic Effects of Girls' Education in Developing Countries

The National Academies Press just released a synopsis of a workshop organized earlier this year by the Population Committee of the National Academy of Sciences on the topic of "Demographic Effects of Girls' Education in Developing Countries." The workshop was headed up by Ann Blanc of the Population Council, Jere Behrman of the University of Pennsylvania and Cynthia Lloyd who is now an independent consultant but was with the Population Council for many years. The main question raised was this: Why does education have an impact on fertility? In other words, what are the causal linkages?

In general, the participants in the workshop (who were all demographers doing work in the area of girl's education and fertility in developing countries--especially in Africa) concluded that an education can change the way a girl thinks about her place in the world and this can influence her decision-making about the timing of both marriage and childbearing. At the same time, having a baby early almost always truncates a girl's education and sets her back for the rest of her life. So, the causal links work in two directions.

I read through the synopsis of the workshop looking for things I didn't already know, and the major point that was brought out that needs some consideration is the idea that the quality of education may actually be lower now than it used to be in some of the countries that were being discussed. If that is true, then the impact of education on attitudes and behaviors of young women may be less than in the past. Still, however, I saw nothing to suggest I should modify the following summary that you will find on page 207-208 in Chapter 6 of the 12th edition of my text:

It is nearly axiomatic that better-educated women have lower fertility than less-educated women in any given society. It is the identification of this kind of fertility differential that helps to build our understanding of reproductive dynamics in human societies, because it causes us to ask what it is about education that makes reproduction so sensitive to it. In general terms, the answer is that education offers to people (men and women) a view of the world that expands their horizon beyond the boundaries of traditional society and causes them to reassess the value of children and reevaluate the role of women in society. Education also increases the opportunity for social mobility, which, in turn, sharpens the likelihood that people will be in the path of innovative behavior, such as fertility limitation, that they may try themselves. Indeed, the role of education is so important that demographers at the Vienna Institute of Demography have created a whole set of population projections incorporating trends in educational attainment as a predictor of fertility levels.

The Demographics of Not Moving to Where the Jobs Are

There seems to be general agreement that Donald Trump's base of support are people who feel they are being left behind by the process of globalization and they want some change. It seems highly unlikely that Trump's proposed tax cuts will help those people, but this week's Economist takes a stab at the problem. 

The general pattern in the past in most countries of the world has been for people to go where the jobs are. My wife's grandfather migrated from Denmark in the late 19th century because there were no jobs there, but there was a chance to be a successful farmer in the American midwest. In my lifetime, my family certainly moved for economic reasons. During the first 12 years of my life, we lived in two different cities in northern California, three cities in Oregon, and one city in Arizona before settling down in San Diego. But Americans are moving less than they used to, according to Census data assembled by the Economist (see below). 

The Economist suggests that several demographic factors may help to understand this slowing of migration. There are now many more two-earner households, making it harder for couples to move (or even to decide where to move if they are going to move). At the same time, people may have older parents who are aging in place and who expect or at least hope that their children and grandchildren will be close enough to help them out. Another major impediment to movement is the high cost of housing in almost all of the urban places that are home to the superstar companies. The higher wages in those places may be offset by the cost of living there. There is also the fact that many unemployment and welfare benefits are place-specific. If you move, you lose those benefits, thus reducing the incentive to move since most people tend to be risk-averse.

The principal suggestion for change proposed by the Economist amounts to local economic development. This could involve a public-private partnership to invest in new types of businesses where globalization has left a labor force looking for work. Going along with this could be an investment in local community colleges geared toward teaching people the skills that these new companies need for success. This is so crazy it might just work.

How Many Births Were Averted in China by the One-Child Policy?

My thanks to Stuart Gietel-Basten for pointing to a story in Science magazine by Mara Hvistendahl about a controversy brewing over how many births were averted in China by their one-child policy.

A new study of China’s one-child policy is roiling demography, sparking calls for the field’s leading journal to withdraw the paper. The controversy has ignited a debate over scholarly values in a discipline that some say often prioritizes reducing population growth above all else.

Chinese officials have long claimed that the one-child policy—in place from 1980 to 2016—averted some 400 million births, which they say aided global environmental efforts. Scholars, in turn, have contested that number as flawed. But in a paper published in the journal Demography in August, Daniel Goodkind—an analyst at the U.S. Census Bureau in Suitland, Maryland, who published as an independent researcher—argues that the figure may, in fact, have merit.

Now, to be honest, I'm not sure that Goodkind's study is "roiling demography," but the paper is, in fact, written in a somewhat contentious style because it is obvious that Goodkind knows that his analysis will likely be unpopular. To be sure, he notes explicitly that his conclusions are different from those of a lot of people, including Stuart Gietel-Basten, and Mara Hvistendahl who wrote this story for Science. 

If you have read Chapter 6 of my book, you will know from Figure 6.9 (see below) that the drop in fertility was very similar in China (where the one-child policy was implemented in 1979) to that in Taiwan, where there was no such policy. 

The Taiwanese are culturally very similar to those in mainland China and, despite the fact that economic development may have taken off a bit earlier in Taiwan than on the mainland, the two countries were already on the same downward fertility path before China implemented its one-child policy. Goodkind tends to dismiss that argument in his paper, preferring to believe that the differences in economic development were more important than the data seem to suggest. 

My reading of Goodkind's paper is that it is much ado about nothing. While one may question the editors of Demography as to whether it should have been accepted for publication, it at least reminded us that there's nothing to see here folks. The one-child policy was a human rights disaster and, in my view, was not necessary to the drop in fertility in China. The Chinese were going to avert those births with or without that policy.