Tag Archives: births

Is there sex selection among Asian immigrants in the US?

There is a 2008 paper reported in the New York Times in 2009, which found skewed sex ratios among children of immigrants from China, Korea, and India, if their older siblings were girls, using the 2000 Census. The implication was that some parents were using IVF or abortion to select boy children if their first two were girls — as is the case in their home countries. There has been some other research on this from the early 2000s, but I haven’t seen it updated since then.

I took a quick stab at it, but don’t have time right now to pursue it more thoroughly. So here’s the quick answer I got, and I shared my data, code, and results in an Open Science Framework project, here. I hope someone will be interested and pursue it further (using my approach or not). The files there include all different ethnic/racial groups.

This is preliminary.

Using the American Community Survey data from 2010-2015, from IPUMS.org, I took U.S.-born children ages 0-5, whose parents were both born in China, Korea, or India and both were present in the household. I counted the sex of any present siblings under age 15 (excluding step- and adopted children). Then I restricted the data to those with 2 older siblings, and compared the sex ratios among those who had 0 or 1 older sister to those who had 2 older sisters. I did this in a logistic regression controlling for individual years of age, and using ACS person weights. There are judgment calls to make about age, siblings, data and other issues. The older you get the more likely you are to have kids moving out in a way that is not sex-neutral (for example, if parents with girls are more or less likely to divorce), and so on. Should parents be matched on immigration status, siblings born abroad included, why the years 2010-2015, and so on. This is what I mean by preliminary. But these results are interesting enough to prompt me to post them and encourage discussion and more analysis.

Here’s what I got:

sex selection.xlsx

The sex differences between those with 0/1 older sister and 2 older sisters are not statistically significant at p.<.05 in each of the three groups, but they are for the combined set (.046). These comparison involve a few hundred cases. Here are the unweighted, unadjusted results:


As you can see, just a few families intervening to choose boys — or some other force rearranging the living arrangements, or survival, of children and families, and the difference would not hold. Still, I think it’s worth pursuing. Maybe someone already has. If you decide to get into it, feel free to use this stuff, and let me know what you come up with!


Filed under Me @ work

How do Black-White parents identify their children?

In 2015 the American Community Survey yields an estimate of 66,913 infants who have one Black parent and one White parent present in the household. (Either parent may be multiracial, too.)

What is the race of those infants? 73% of them were identified as both White and Black by whoever filled out the Census form.


(Note “other” doesn’t mean they specified “other,” it just means they used some other combination of races.)

These are children age 0 living with both parents, so it’s a pretty good bet they’re mostly biological parents, though some are presumably adopted. This is based on a sample of 507 such infants. If you pooled some years of ACS there is plenty to study here. Someone may already have done this – feel free to post in the comments.

That’s it, just FYI.

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Filed under In the news

If the National Marriage Project told you it was going to rain, would you bring an umbrella?

Why do academics and journalists lend legitimacy to the National Marriage Project?

The Centers for Disease Control: You bought that.

The Centers for Disease Control: You bought that.

I today’s New York Times Week in Review, Andrew Cherlin offers this:

Having a child outside of marriage has also become common. According to a report by the National Marriage Project at the University of Virginia, 47 percent of American women who give birth in their 20s are unmarried at the time.

It took me 3 minutes to find the the 2010 report on birth data from the National Center for Health Statistics (NCHS), a branch of the Centers for Disease Control, and another 1/2 minute to locate the table with this information, which is table 15. Because of my weakness in algebra, it took me another 5 minutes to turn the number of babies born to unmarried women in the age range 20-24 (600,833) and in the age range 25-29 (384,865) and the percent unmarried that those represented (63.1% and 33.9%, respectively), into the total births to women in their 20s (2,087,487) and the percentage of all those to unmarried women (47.2%).

The New York Times paid for that statistic through taxes, which its government has provided. So why publish an essay by a sociologist with a named chair crediting the National Marriage Project, a right-wing front run by the discredited Brad Wilcox on behalf of big-money Christian conservatives? (In other news, the Heritage Foundation reported that the unemployment rate in February was 7.7%).

Maybe the media establishment simply doesn’t know a simple government statistic when they see one. But they see the university label and fancy website, and guy with the (implied) elbow patches, and they think the number is more complicated than it looksRather than hire a qualified unpaid intern to check facts and credit them to their actual sources, maybe they just trust the experts they rely on. (This is the David Brooks strategy.)

With resources for journalism and social science research on the decline, and foundation money playing a growing role in providing information to the media, this is predictable – but still lamentable.


Filed under Uncategorized

Yes, mothers and fathers still exist

On FamilyScholars.org, which (having retreated on opposing homogamous marriage) is busy promoting its “new conversation on marriage,” Elizabeth Marquardt writes: “Where do babies come from? The state of New York seems unsure.”

Her link to a “report” is to one of those “you wouldn’t believe what my friend saw” posts on the Christian conservative site First Things:

A friend’s wife recently gave birth. He reports that the New York birth certificate asks for the sex of the mother, and the sex of the father.

It goes on to mock people who think seriously about sex and gender. And so the thing starts spreading around the religious-conservative sky-is-falling blogosphere.


I’m not too embarrassed to say I spent 15 minutes trying to look this up. Live and learn.

It’s hard to find information about birth certificates, because everything online keeps steering you to ways to order birth certificates, not create them. But, in New York state it appears there is a state system, and a state system excluding New York City. On the New York City site, there is an Electronic Birth Registration System, described here. It asks for a lot of information about the mother and father, but not their sex or gender.

I didn’t find the equivalent for the rest of the state, but the state’s Department of Health reports that they follow National Center of Health Statistics (NCHS) guidelines, which seem to refer to this revised birth certificate recording form, which was revised in 2003. In addition to health information, it records the mother’s and father’s marital status (mother only), country of birth, education, Hispanic origin, and race. The mother is “the woman who gave birth to, or delivered the infant.”

The only mention of sex (or gender) pertains to the child: “Print or type whether the infant is male, female or if the sex of the infant is not yet determined.” And “not yet determined” is a temporary state, as the recording instructions clarify:

An N code for “not yet determined” should not be allowed for any record in the file at the time the file is closed. NCHS will query states to obtain the sex of the infant for all records still retaining the N code at the time the file is closed.



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Births to mothers in their forties are less common now than in the old days

In my post the other day I suggested that, when it comes to children’s health, mothers’ health is a bigger issue than mothers’ (advancing) age when they give birth. I was motivated to post it by the widespread discussion of Judith Shulevitz’s essay in the New Republic, “How Older Parenthood Will Upend American Society” — discussion that has continued with today’s On Point (which I haven’t heard yet), including the author Elizabeth Gregory, who has written Ready: Why Women Are Embracing the New Later Motherhood (which I haven’t read yet).

In the comments, several people (Reeve Vannamen and relfal) brought up the issue of later births in the olden days (before 1970). We need to think about two different issues: having first children at a later age, and having any (or many) children at a later age. For some questions of children’s health – especially the sperm-mutation issue with autism – I don’t think it matters: an older-age birth is an older age birth. The same goes for the angst over whether children will know their grandparents, whether parents will be too old to take them to soccer practice, and so on.

On the other hand, “starting a family” at an older age (because, remember, it’s not a “family” until you have kids), is a different issue, with its own implications for total fertility rates, the age composition of the population, etc.

Both having any children and having first children at older ages have been increasing in recent decades, but having any children at older ages is not historically unprecedented. Here are the birth rates for women ages 40-44, from 1940 to 2011, along with the percentage of all children born to those women from 1960-2010:


Sources: Birth rates 1940-1969, 1970-2010, 2011; Percent of births 1960-1980, 1980-2008.

Birth rates to women ages 40-44 are still substantially lower than they were in the olden days. So the number of kids whose parents will be over 60 when the kids come back to live with them after college is lower now despite an increase for 30 years.

On the other hand, the percentage of kids born to older mothers has surpassed those rates, because these are more often first or second, rather than third or fourth or fifth children. Put another way, the chance that women will have their first, and possibly only, baby at an older age has increased since 1960. While the overall birth rate for older women is still lower than it was in 1960, the first-birth rate is much higher. Here is the birth rate among women with no previous births, for those aged 35, 40 and 45, from 1960 to 2005:

first birth rates 60-05

Source: Table 4 on this page.

In 1960, only 4% of women who reached age 35 without having a baby had one that year. They probably weren’t just delaying their childbearing intentionally or putting off finding a mate while they pursued their careers. On the other hand, by 2005 almost 9% of those who reached age 35 without having a baby had one that year. The late first birth has become much more common.

Now if you go back to the promo blurb for On Point, you see how the issues are jumbled together:

American parents are having kids old and older. Look around. Are those two that child’s parents? Or its grandparents? It is very often hard to know these days. In many ways, this has been liberating. Twenty-somethings with a child-free, diaper-free decade of youth. People with time and space to start careers. But there is a price, and it’s becoming clearer. Older parents juggling kid’s soccer and their own aches and pains. Kids who won’t know their grandparents. Parents who won’t know their grandkids. And a baby bust.

The hardships faced by older parents are nothing new, but parents used to have more kids around when they went through them. It’s good to keep an eye on the issues separately.

Note: there is some more background and analysis in my working paper: here.



Filed under In the news, Me @ work

Study shows home births are not as safe. So?

There’s an interesting example of how to interpret scientific results — and draw policy implications from them — from the world of birth practices and safety.

The subject of the debate is a major new study from the British Medical Journal. The study followed more than 60,000 women in England with uncomplicated pregnancies, excluding those who had planned caesarean sections and caesarean sections before the start of labor. They compared the number of bad outcomes — from death to broken clavicles — for women depending on where they had their births.

One comparison stands out in the results. From the abstract: “For nulliparous women [those having their first birth], the odds of the primary outcome [that is, any of the negative events] were higher for planned home births” than among those planned for delivery in obstetric units. That is, the home births had higher rates of negative events. The difference is large. Here’s a figure to illustrate:

The error bars show 95% confidence intervals, so you can see the difference between home births and obstetric-unit births is statistically significant at that level. These are the raw comparisons, but the home-versus-obstetric comparison was unchanged when the analysts controlled for age, ethnicity, understanding of English, marital or partner status, body mass index, “deprivation score,” previous pregnancies, and weeks of gestation. Further, by restricting the comparison to uncomplicated pregnancies and excluded all but last-minute c-sections, it seems to be a very strong result.

But what to make of it?

In their conclusion, the authors write:

Our results support a policy of offering healthy nulliparous and multiparous women with low risk pregnancies a choice of birth setting. Adverse perinatal outcomes are uncommon in all settings, while interventions during labour and birth are much less common for births planned in non-obstetric unit settings. For nulliparous women, there is some evidence that planning birth at home is associated with a higher risk of an adverse perinatal outcome.

But in what way do the results “support a policy”? The “higher risks” they found for planned home births are still “uncommon,” by comparison, with those in poor countries, for example. But the home birth risk is 2.7-times greater.

The Skeptical OB, who is a reliable proponent of modern medical births, titled her post, “It’s official: homebirth increases the risk of death.” She added some tables from the supplemental material, showing the type of negative events and conditions that occurred. Her conclusion:

“In other words, any way you choose to look at it, no matter how carefully you slice and dice the data, there is simply no getting around the fact that homebirth increases the risk of perinatal death and brain damage.”

I guess the policy options might include include whether home births should be encouraged, more regulated, covered by public and/or private health insurance, banned, penalized or (further) stigmatized.

Home birth seems safer than letting children ride around unrestrained in the back of pickup trucks, which is legal in North Carolina — as long as they’re engaged in agricultural labor. On the other hand, we have helmet laws for kids on bicycles in many places. And if a child is injured in either situation, hopefully an ambulance would take them to the hospital even if the accident were preventable.

In other words, I don’t think policy questions can be resolved by a comparison of risks, however rigorous.


Filed under In the news, Research reports

Fertile decline

The numbers are starting to add up.

U.S. Senator Rick Santorum blamed abortion for the lack of young workers to pay for Social Security: “Well, a third of of all the young people in America are not in America today because of abortion — because one-in-three pregnancies end in abortion.” If he was right about that, he should consider blaming someone for the recession.

The latest data brief from the National Center for Health Statistics offers the strongest evidence yet that the recession has driven birth rates down.

Here are three ways the evidence points toward the recession decreasing Americans’ production of children. First, the timing: 2009 saw the largest single-year drop in fertility rates since the early 1970s. Here is my graph of annual change in the number of live births per 1,000 women ages 15-44 (sometimes called the “general fertility rate”):

The decline is very broad — affecting all race-ethnic groups, almost all states, and all ages of women (except the oldest). However, I’m taken by a second pattern, which shows the declines steepest at the higher birth orders — so the people who are most affected are those who already have kids, which fits the idea of families embracing the new austerity in place of the old three-is-the-new-two gestalt that seems so mid-2000s now:

I wrote a longer post on this last fall, in which I summarized the argument that this recession was serious business for birth rates:

If you put together busted real estate values and increasing education costs, collapsing state services increasing insecurity, and tightened access to credit, then the resulting “era of thrift” in the culture of consumption might include fewer children among both rich and poor. There is room for such a change, as a very serious “correction” would still only take the U.S. down to the level of its economic peers.

At the time I quoted this 2010 Pew report, which concluded: “Birth rates in the United States began to decline in 2008 after rising to their highest level in two decades, and the decrease appears to be linked to the recession”. In it, the analysts compared home prices and per capita income changes in states with changes in fertility, which showed a consistent pattern of greater birth declines in harder-hit states.

With the new data new birth data by state, and state unemployment rates from the Bureau of Labor Statistics, I can extend that now, and I think it’s a pretty strong third point: fertility fell more where the recession hit harder. The state-level correlation between changing fertility rates in 2007-2009 and changing unemployment rates in 2006-2008 is .48 on a scale of 0 to 1. (I figured it made sense to take unemployment rates from the year previous.) Here is the pattern:

It remains to be seen whether this is a small correction, or even just a delay, in birth rates on account of the economic crisis. Compared with the other rich countries, the U.S. still has high fertility rates. And in the long run that might be a more important issue than the recent fluctuations.


Filed under In the news