How Long Can You Wait to Have a Baby?

Sunday, June 30th, 2013

Science reporting is bad, and the popularized statistics on women’s age and fertility are no exception:

The widely cited statistic that one in three women ages 35 to 39 will not be pregnant after a year of trying, for instance, is based on an article published in 2004 in the journal Human Reproduction. Rarely mentioned is the source of the data: French birth records from 1670 to 1830. The chance of remaining childless—30 percent—was also calculated based on historical populations.

In other words, millions of women are being told when to get pregnant based on statistics from a time before electricity, antibiotics, or fertility treatment. Most people assume these numbers are based on large, well-conducted studies of modern women, but they are not. When I mention this to friends and associates, by far the most common reaction is: “No … No way. Really?”

Surprisingly few well-designed studies of female age and natural fertility include women born in the 20th century—but those that do tend to paint a more optimistic picture. One study, published in Obstetrics & Gynecology in 2004 and headed by David Dunson (now of Duke University), examined the chances of pregnancy among 770 European women. It found that with sex at least twice a week, 82 percent of 35-to-39-year-old women conceive within a year, compared with 86 percent of 27-to-34-year-olds. (The fertility of women in their late 20s and early 30s was almost identical—news in and of itself.) Another study, released this March in Fertility and Sterility and led by Kenneth Rothman of Boston University, followed 2,820 Danish women as they tried to get pregnant. Among women having sex during their fertile times, 78 percent of 35-to-40-year-olds got pregnant within a year, compared with 84 percent of 20-to-34-year-olds. A study headed by Anne Steiner, an associate professor at the University of North Carolina School of Medicine, the results of which were presented in June, found that among 38- and 39-year-olds who had been pregnant before, 80 percent of white women of normal weight got pregnant naturally within six months (although that percentage was lower among other races and among the overweight). “In our data, we’re not seeing huge drops until age 40,” she told me.

Even some studies based on historical birth records are more optimistic than what the press normally reports: One found that, in the days before birth control, 89 percent of 38-year-old women were still fertile. Another concluded that the typical woman was able to get pregnant until somewhere between ages 40 and 45. Yet these more encouraging numbers are rarely mentioned—none of these figures appear in the American Society for Reproductive Medicine’s 2008 committee opinion on female age and fertility, which instead relies on the most-ominous historical data.

In short, the “baby panic”—which has by no means abated since it hit me personally—is based largely on questionable data. We’ve rearranged our lives, worried endlessly, and forgone countless career opportunities based on a few statistics about women who resided in thatched-roof huts and never saw a lightbulb. In Dunson’s study of modern women, the difference in pregnancy rates at age 28 versus 37 is only about 4 percentage points. Fertility does decrease with age, but the decline is not steep enough to keep the vast majority of women in their late 30s from having a child. And that, after all, is the whole point.


Studies of natural conception are surprisingly difficult to conduct—that’s one reason both IVF statistics and historical records play an outsize role in fertility reporting. Modern birth records are uninformative, because most women have their children in their 20s and then use birth control or sterilization surgery to prevent pregnancy during their 30s and 40s. Studies asking couples how long it took them to conceive or how long they have been trying to get pregnant are as unreliable as human memory. And finding and studying women who are trying to get pregnant is challenging, as there’s such a narrow window between when they start trying and when some will succeed.

Another problem looms even larger: women who are actively trying to get pregnant at age 35 or later might be less fertile than the average over-35 woman. Some highly fertile women will get pregnant accidentally when they are younger, and others will get pregnant quickly whenever they try, completing their families at a younger age. Those who are left are, disproportionately, the less fertile. Thus, “the observed lower fertility rates among older women presumably overestimate the effect of biological aging,” says Dr. Allen Wilcox, who leads the Reproductive Epidemiology Group at the National Institute of Environmental Health Sciences. “If we’re overestimating the biological decline of fertility with age, this will only be good news to women who have been most fastidious in their birth-control use, and may be more fertile at older ages, on average, than our data would lead them to expect.”

Tyler Cowen on World War Z

Saturday, June 29th, 2013

I haven’t seen World War Z, but Tyler Cowen has:

I was surprised how serious a movie it is and also by how deeply politically incorrect it is, including on “third rail” issues such as immigration, ethnic conflict, North Korean totalitarianism, American urban decay as exemplified by Newark, gun control, Latino-Black relations, songs of peace, and the Middle East. Here is one (incomplete) discussion of the Middle East angle, from the AP, republished in el-Arabiya (here is a more detailed but less responsible take on the matter, by a sociology professor and Israeli, spoilers throughout).

The movie is set up to show sympathy for the “Spartan” regimes and to have a message which is deeply historically pessimistic and might broadly be called Old School Conservative, informed by the debates on martial virtue from pre-Christian antiquity. But they recut the final segment of the movie and changed the ending altogether, presumably because post-Christian test audiences and film executives didn’t like it. Here is one discussion of the originally planned finale. It sounds good to me. The actual movie as it was released reverts to a Christian ending of sorts. My preferred denouement would have relied on the idea of an asymptomatic carrier or two, go see it and figure out the rest yourself.

Christopher Lee: Metal Rocker and Total Badass

Saturday, June 29th, 2013

Christopher Lee was a total badass long before he played Saruman, Dooku, or Dracula:

He witnessed the last execution via guillotine in France. He fought in the Winter War in Finland in 1939. He was in the SAS in North Africa during the War. He was cousin to Ian Flemming, who tried (and failed) to get him cast as Dr. No (he had to wait until Man With The Golden Gun to play a Bond villain).

But this post is about his musical career which is nothing short of amazing. He had classical voice lessons to develop a basso profondo operatic capability. He’s continued his recording career, most recently with the Symphonic Metal band Rhapsody Of Fire.

Sleep Deprivation in Hospitals Is a Real Problem

Saturday, June 29th, 2013

Sleep is important for your health, but hospitals keep their patients from sleeping:

Recently I was all-too-miserably reminded of the challenges of hospital sleep when I spent a fitful night recovering from surgery to remove a small kidney tumor. Unlike some patients in that situation, my sleep was not disturbed by pain or nausea; I was lucky to avoid both of those postoperative complications. Instead, my sleep was interrupted, hourly, by clinicians taking care of me. There were vital sign checks every four hours, a frequency that makes sense given that I had just had part of my left kidney removed. Sometimes sleep interruptions are necessary in order to monitor patient conditions. But those vital sign checks, at midnight and 4 a.m., were not the only interruptions I experienced that night. At 3 a.m., if my very foggy memory serves me correctly, someone came into my room to draw blood for follow-up laboratory tests. Several other times that evening, the machine hovering near my left ear beeped to tell me that one of my IV medications had run out; I would push the nursing button and tell the person at the desk about the beeping, and eventually someone would come in and either replace the empty IV bag or turn the alarm off.

Between 10 p.m. and 6 a.m., I did not go more than an hour without some kind of interruption.

As I have already suggested, some of these interruptions are necessary. But many are not. And the consequence of too many sleep interruptions is that patients do not heal as quickly as they would otherwise, thereby not only reducing their quality of life but also driving up medical costs. Indeed, as I have written elsewhere: sleep disturbance is a leading cause of hospital complications, such as falls and delirium. Poor sleep has also been linked to reduced immune function,worsening blood pressure control and mood disorders. All of these problems potentially impair the ability of patients to recover from the acute illnesses that caused them to be hospitalized.

It’s infuriating, really. So, how do we fix things? Well, the answer is simple — if not easy:

First, hospitals could make simple organizational changes. During my recent hospital stay, for example, a major contributor to my interrupted sleeping was the specialization of tasks across different hospital personnel. When the IV machine beeped, it was the nurse who helped out, her training being necessary to monitor the IV lines and medications. When it came to measuring my vital signs, though, a nurse’s aide was sent to accomplish the task. And a phlebotomist came to draw my blood. Specialization matters. The doling out of these duties to different people — with different skills and different pay grades — makes great economic sense, and in many ways improves hospital quality of care. But such specialization interferes with sleep, because the different people performing each of these duties enter patient rooms at different times of the night.

There is a better way to coordinate these various clinicians to reduce sleep interruptions. For example, phlebotomists could coordinate their work with nursing aides. Imagine that instead of coming into patient rooms one hour apart from each other, the two came in together: “We are here to check your blood pressure and draw some blood,” they would say (maybe even in unison!). That little change would eliminate one interruption. A second change could also improve patient sleep: more flexibility in the timing of vital sign measures. If, for example, a patient’s IV machine beeps at 11 p.m. and the next check of her vital signs is due at midnight, the nurse could bump up the vital sign measures by an hour, since the patient is already awake.

Four Chords

Friday, June 28th, 2013

I somehow missed The Axis of Awesome‘s “Four Chords” when it came out:

I immediately recognized some of the songs in that official music video:

  1. Journey – “Don’t Stop Believin’”
  2. James Blunt – “You’re Beautiful”
  3. Black Eyed Peas – “Where Is the Love”
  4. Alphaville – “Forever Young”
  5. Jason Mraz – “I’m Yours”
  6. Train – “Hey Soul Sister”
  7. The Calling – “Wherever You Will Go”
  8. Elton John – “Can You Feel The Love Tonight” (from The Lion King)
  9. Akon – “Don’t Matter”
  10. John Denver – “Take Me Home Country Roads”
  11. Lady Gaga – “Paparazzi”
  12. U2 – “With Or Without You”
  13. The Last Goodnight – “Pictures of You”
  14. Maroon Five – “She Will Be Loved”
  15. The Beatles – “Let It Be”
  16. Bob Marley – “No Woman No Cry”
  17. Marcy Playground – “Sex and Candy”
  18. Men At Work – ” Down Under”
  19. Jill Colucci – “The Funny Things You Do” (Theme from America’s Funniest Home Videos)
  20. Jack Johnson – “Taylor”
  21. Spice Girls – “2 Become 1″
  22. a-ha – “Take On Me”
  23. Green Day – “When I Come Around”
  24. Eagle Eye Cherry – “Save Tonight”
  25. Toto – “Africa”
  26. Beyoncé – “If I Were A Boy”
  27. Kelly Clarkson – “Behind These Hazel Eyes”
  28. Jason DeRulo – “In My Head”
  29. The Smashing Pumpkins – “Bullet With Butterfly Wings”
  30. Joan Osborne – ” One of Us”
  31. Avril Lavigne – “Complicated”
  32. The Offspring – “Self Esteem”
  33. The Offspring – “You’re Gonna Go Far, Kid”
  34. Akon – “Beautiful”
  35. Timbaland featuring OneRepublic – “Apologize”
  36. Eminem featuring Rihanna – “Love the Way You Lie”
  37. Bon Jovi – “It’s My Life”
  38. Lady Gaga – “Poker Face”
  39. Aqua – “Barbie Girl”
  40. Red Hot Chili Peppers – “Otherside”
  41. The Gregory Brothers – “Double Rainbow Song”
  42. MGMT – “Kids”
  43. Andrea Bocelli – “Time To Say Goodbye”
  44. Robert Burns – “Auld Lang Syne”
  45. Five for Fighting – “Superman”
  46. The Axis of Awesome – “Birdplane”
  47. Missy Higgins – “Scar”

Josh Kaufman plays the medley on his ukulele while promoting The First 20 Hours, his book about how to learn anything fast:

Living in a Dictatorship

Friday, June 28th, 2013

How does one tell whether one is living in a dictatorship, or almost?

The signs need not be so obvious as having a squat little man raving from balconies. Methinks the following indicators serve. In a dictatorship:

(1) Sweeping laws are made without reference to the will of the people. A few examples follow. Whether you think these laws desirable is not the point. Some will, others won’t. The point is that they were simply imposed from above. Many of them would never have survived a national vote.

Start with Roe vs. Wade, making abortion legal, and subsequent decisions allowing late-term abortion. Griggs versus Duke Power, forbidding employers from using tests of intelligence, since certain groups scored poorly. Brown versus the School Board and its offspring requiring forced integration, forced busing, racial quotas, and so on. The decision that Creationism cannot be mentioned in the schools. Decisions forbidding the public expression of Christianity. The decision that citizens can be stopped and searched without probable cause. The opening of the borders to mass immigration.

These are major, major laws grossly altering the social, legal, and constitutional fabric of the country. All were simply imposed, mostly by unelected judges against whom there is no recourse.

Note that there is no practical distinction between a decision by the Supreme Court, a regulation made by an executive bureaucracy, and a practice quietly adopted by the intelligence agencies and federal police. None of these requires public approval.

For that matter, consider the militarization of the police, the creation of Homeland Security’s Viper teams that randomly search cars, the vast and growing spying on Americans by government, and the genital gropings by TSA. Consider the endless undeclared wars that one finds out often only after the troops have been sent. All simply imposed from above.

In principle, elected officials represent the desires of their electorates. In practice Congress barely touches on most issues of concern to the public. Overturning any of the aforementioned types of laws is virtually impossible.

(2) Another measure of dictatorship is the extent to which the people fear the government. A time was when governmental official in general, and the police in particular, had to be cautious in pushing the citizenry around. A justified complaint to the chief of police brought consequences. Today the police can do as they please, and you have no recourse. The new aggressiveness applies especially to federal police. If you object to excessive intrusion by agents of TSA, they will make sure you miss your flight. In principle you can complain, but in practice the effect is zero.

(3) Dictatorships characteristically watch the citizenry very carefully, using the secret police and encouraging people to inform on each other. Both are now routine. Did you vote to have your email read, your telephone calls recorded, your browsing habits on the web turned over to the NSA or the FBI? No. And you have no recourse.

To one raised in a freer United States, it is astonishing to hear on the subway of Washington, DC constant admonitions to watch one’s fellow passengers and report “suspicious behavior.”


Friday, June 28th, 2013

American drivers — well, outside a few cities — are used to driving without ever hearing anyone honk their horn.

Indian drivers honk all the time. Literally. Trucks have “please honk” signs — that’s how they know you’re there.

The new Bleep horn reduction system is designed to reduce honking to just useful alerts:

Maria Sharapova’s Video Analysis

Thursday, June 27th, 2013

In the last few months, Maria Sharapova has hired a video-analysis expert to help her beat Serena Williams:

O’Shannessy’s videos show patterns that work — and fail — against Williams. He calls the open court “an illusion,” because Williams excels at being aggressive while moving to the open court. The solution: Hit behind Williams as often as possible, forcing her to move in one direction, reset her feet, and then go back in the other direction.

Opponents look to attack Williams’s forehand crosscourt, since that’s where she makes most of her errors. Still, Sharapova too often takes risks down the line, O’Shannessy said, especially from defensive positions. And she hits too many backhands from the middle of the court, when she has time to sidestep and hit forehands.

This isn’t the first time Sharapova has relied on video. At the 2006 U.S. Open, she went into the final against Justine Henin having lost their last four matches, including their semifinal at that year’s Australian Open. Joyce’s father, a former photography director for television shows such as “Little House on the Prairie” and “CHiPs,” scoured Henin video to suggest tactics for Sharapova.

“Henin had extreme grips,” Joyce said. “My dad said, ‘If Maria can hit down the middle and make her switch grips as often as possible, she’ll get more errors.’” Sharapova won, 6-4, 6-4.

Drug Testing in 1984

Thursday, June 27th, 2013

The U.S. Olympic Committee conducted an informal drug testing program in the months leading up to the 1984 Summer Olympic Games in Los Angeles Games that allowed Olympic-caliber athletes testing positive for banned substances to escape sanctions:

At least 34 U.S. track and field athletes either tested positive or had possible positive tests during six weeks of informal testing by USOC in the spring of 1984, according to confidential USOC memos. None of the athletes was sanctioned or lost eligibility, according to USOC documents and interviews.

Athletes were informed of their positive tests and told continued use of banned drugs could result in positive tests at the U.S. Olympic Trials and Olympic Games, where violations would lead to bans from competition.
“It gave them a heads up,” said Ollan Cassell, executive director of U.S. track and field’s governing body from 1980 to 1997. “It let them know what was coming, what to expect.”


“It’s not fair, it’s not right,” Dr. Irving Dardik, in 1984 the chairman of USOC sports medicine council, said of the informal testing program. “If an athlete tested positive, they should have been penalized.”

Dardik said he hand delivered his report to Robert H. Helmick shortly after Helmick took over as USOC president in early 1985. Three weeks later, Dardik asked Helmick about the report.

“Helmick said ‘What report?’ ” Dardik recalled. “It was clear you were not to make any waves that could in anyway implicate the internal workings of (U.S. track’s governing body) or the USOC.”

Victor Conte

Thursday, June 27th, 2013

Joe Rogan interviews Victor Conte of BALCO fame:

He mentions ESPN’s 9.79 documentary and an old OC Register article.

Home Invasion Footage

Wednesday, June 26th, 2013

This nanny-cam footage of a home invasion in Millburn, New Jersey should make your blood boil:

A significant number of criminals report that they feel a sense of accomplishment when they commit a crime:

Let me put that in terms you’ll understand: Think about how you felt when you graduated from college, or when you bought your first house, or when you snagged that promotion you worked so hard for, or when you lost that extra weight, or when you completed that big project. Think about what it did for your self worth. Think about what it did for your mood. Do you have it in your mind? Good.

That’s how this guy felt after beating that defenseless woman bloody in front of her small child.

Now I ask you:

Are you willing to let that into your home unchallenged? When that breaks into your home are you going to assume it just wants your jewelry and DVD player? Or perhaps the medications your recently deceased husband was taking to ease his pain from terminal cancer? Are you going to let them have free reign and hope they don’t hurt the people you love?

When a criminal kicks in your door you do not have the luxury of assuming they’ll go away and leave you unhurt if you just give them what they want. You don’t have the luxury of waiting for 911 or the alarm company to send help.

What Did the Kindergarten Study Really Find?

Wednesday, June 26th, 2013

How Does Your Kindergarten Classroom Affect Your Earnings?” is one of the most impressive empirical papers ever written, Bryan Caplan says:

The data collection is amazing. The empirical analysis is clear and careful. Above all else, the authors’ methods are transparent. Lesser authors would have buried the conflicting findings. Chetty et al. took the high road.

Unfortunately, the world is so eager for stories about the power of early education that their paper is being badly misinterpreted.

How so?

Here’s what they really find about the effect of early schooling on adult income:

1. Project STAR was an experiment designed to test the effect of class size. The experiment found that students assigned to small classes earned $4 more per year. If you add demographic controls, students assigned to small classes earned $124 less per year. (more)

2. You can use Project STAR’s data to (non-experimentally**) test for other effects. When you do, almost all measures of teacher quality fail to increase adult earnings:

The few other observable teacher characteristics in the STAR data (degrees, race, and progress on a career ladder) have no significant impact on scores or earnings.

3. There is one measure of teacher quality that does matter: Whether the teacher has more than 10 years of experience. Chetty et al. find that students assigned to a kindergarten teacher over this experience cut-off eventually earn $1093 extra dollars per year. But bear two reservations in mind. (a) The t-stat is only 2.4 — extremely low for a non-experimental test with 6005 observations. (b) If you measure experience in years, rather than using their binary “more than 10 years of experience” variable, the point estimate is a statistically insignificant $57 per year.

4. Teacher experience only matters in kindergarten:

The effect of teacher experience on test scores is no longer statistically significant in grades 1-3. Consistent with this result, teacher experience in grades 1-3 also does not have a statistically significant effect on wage earnings.

By my count, Chetty et al. have five measures of teacher quality (degrees, race, progress on a career ladder, >10 years experience, and years of experience), study four different grades (K, 1, 2, and 3), and discover precisely one statistically significant effect on income. With 20 different measures, you’d expect one to be statistically significant at the 5% level by chance alone. And these are just the non-experimental results. Experimentally, Project STAR finds that class size does not raise adult income.

Teach Kids to Code

Wednesday, June 26th, 2013

There seem to be quite a few tools for teaching kids to code.

Mitchel Resnick suggests that kids should learn to code so they can code to learn.

Is Government Over-Regulated?

Tuesday, June 25th, 2013

Leave it to Robin Hanson to ask, is government over-regulated?

I heard a talk recently by Jal Mehta on his new book Allure of Order, where he says how he’d reform US (pre-college) schools. He wants the US to do like Finland where schools are great: select smarter folks as teachers, train them more, and give them more respect, time to prepare, and freedom to structure classes. When I asked him directly how he would pay for all this, he said to cut administration.

It seemed to me that Mehtra’s main complaint is that US teachers are over-regulated. And it occurs to me that this is a common complaint about US government. For example, we hear that US police are over-constrained by rules. And a similar problem would befall US single player health plans — while the UK National Health Service has lots of discretion that is mostly accepted by the UK public, US versions would instead be regulated in great detail.

If you think that private actors in the US tend to be over-regulated, you should wonder why. Perhaps it is because government regulators just act spitefully toward non-government actors, but more plausible are over-confidence and do-something biases. When problems occur, people want something done, and more regulations are something to do. Voters and regulators both overestimate their ability to anticipate future problems and what would help them.

But if this is why US private actors are over-regulated, then US government actors should be over-regulated too. For example, people should see things go wrong in schools, and so add more rules to “do something,” rules that assume too much about what rules can do, and that require too many administrators to implement.

This seems to be a common symptom of bureaucracies, which lack a profit motive, where the incentive is instead to demonstrate that you did something.

Dietary Fructose Causes Liver Damage in Monkeys

Tuesday, June 25th, 2013

Dietary fructose causes liver damage in monkeys:

In a previous trial which is referenced in the current journal article, Kavanagh’s team studied monkeys who were allowed to eat as much as they wanted of low-fat food with added fructose for seven years, as compared to a control group fed a low-fructose, low-fat diet for the same time period. Not surprisingly, the animals allowed to eat as much as they wanted of the high-fructose diet gained 50 percent more weight than the control group. They developed diabetes at three times the rate of the control group and also developed hepatic steatosis, or non-alcoholic fatty liver disease.

The big question for the researchers was what caused the liver damage. Was it because the animals got fat from eating too much, or was it something else?

To answer that question, this study was designed to prevent weight gain. Ten middle-aged, normal weight monkeys who had never eaten fructose were divided into two groups based on comparable body shapes and waist circumference. Over six weeks, one group was fed a calorie-controlled diet consisting of 24 percent fructose, while the control group was fed a calorie-controlled diet with only a negligible amount of fructose, approximately 0.5 percent.

Both diets had the same amount of fat, carbohydrate and protein, but the sources were different, Kavanagh said. The high-fructose group’s diet was made from flour, butter, pork fat, eggs and fructose (the main ingredient in corn syrup), similar to what many people eat, while the control group’s diet was made from healthy complex carbohydrates and soy protein.

Every week the research team weighed both groups and measured their waist circumference, then adjusted the amount of food provided to prevent weight gain. At the end of the study, the researchers measured biomarkers of liver damage through blood samples and examined what type of bacteria was in the intestine through fecal samples and intestinal biopsies.

“What surprised us the most was how quickly the liver was affected and how extensive the damage was, especially without weight gain as a factor,” Kavanagh said. “Six weeks in monkeys is roughly equivalent to three months in humans.”

In the high-fructose group, the researchers found that the type of intestinal bacteria hadn’t changed, but that they were migrating to the liver more rapidly and causing damage there. It appears that something about the high fructose levels was causing the intestines to be less protective than normal, and consequently allowing the bacteria to leak out at a 30 percent higher rate, Kavanagh said.