Tuesday, December 31, 2013

Summing up 2013

A brief summary of the year at data insights...


If you could sum up your year in a word, what would it be?

Maternity


Best read

I could pick a journal article, Atlantic Cities post, or other academic-sounding treatise... but the best non-fiction I read in 2013 was a fascinating family history titled Elizabeth Street.

The book documents the life of several families of immigrants recently arrived in New York. It is both social history and biography. And it is totally compelling - especially as the heroine single-handedly wins a battle against local mob thugs.


Best conference experience?

I talked about Poisson distributions at PAA.

I skipped SDA because the FAA wouldn't let me fly on my due-date, but my prior-year paper - comparing administrative records data to census counts - was published in Population Research and Policy Review!


Most popular post?

Perhaps not surprisingly, given the publicity it generated, my guide for where to go for federal data during the shutdown was the most popular post of all time for this blog.



Thank you all for sticking around in 2013!

Friday, November 8, 2013

Maternity leave

As a good demographer, I should report that in the next few days my household will be adding a record to the local vital events registry.

I suspect this child will be one among many in a wave of post-recession babies... I will not go so far as to call 2013 births a "baby boom." (Though it may seem like one after years of falling birth rates.) But 2012 birth data already show that the birth rate stopped falling, and if the volume of appointments at my clinic are any indication, 2013's rates are likely to be higher.

Broader demographic trends aside, my primary reason for writing is to let readers know that this blog (and this blogger) will be on maternity leave for a few weeks.



Before I go... I leave you with this piece on seasonality in prematurity and high birth weight.

Monday, November 4, 2013

What is killing white women?

An article by Monica Potts, "What's Killing Poor White Women?" led sociologist Erin Hoekstra to ask "Why Are Poor White Women Dying Younger than Their Moms?" (It should be noted that while the titles refer to "poor" women, both authors really mean women who lack at least a high school education.)

The authors note that among "white women who don’t graduate from high school... life expectancy has declined dramatically over the past 18 years."

Both authors imply that education and economic opportunity are likely the root of the problem. Potts writes:
Researchers have long known that high-school dropouts like Crystal are unlikely to live as long as people who have gone to college. But why would they be slipping behind the generation before them? James Jackson, a public-health researcher at the University of Michigan, believes it’s because life became more difficult for the least-educated in the 1990s and 2000s. Broad-scale shifts in society increasingly isolate those who don’t finish high school from good jobs, marriageable partners, and healthier communities. “Hope is lowered. If you drop out of school, say, in the last 20 years or so, you just had less hope for ever making it and being anything,” Jackson says. “The opportunities available to you are very different than what they were 20 or 30 years ago. What kind of job are you going to get if you drop out at 16? No job.”
While that may be true, (and indeed, education is linked to longer life expectancy in general) I suspect it is only part of the answer. Some of the decline may be even more basic: selection bias.

Women, particularly white women, have made huge gains in educational attainment and earnings in the past several decades. While the wage gap and other inequalities remain, progress is undeniable for a substantial proportion of women. But perhaps only the healthiest white women are taking advantage of this progress.

Perhaps there is a third factor contributing to both low educational attainment and poor health of white high school dropouts. Perhaps high school dropouts are subject to social, health, or emotional problems that result in both dropping out and poor(er) health.

Friday, November 1, 2013

Data links roundup (week of November 1, 2013)

The week's top data analysis links...
This week's theme: correlation vs. causality, and other odds and ends


UNHEALTHY CHOICE?

In yet another entry into the "correlation does not equal causation" category, there is a strong, positive correlation between autism and... organic produce!


10 CRIME MYTHS, DEBUNKED

The Urban Institute debunks 10 popular crime myths, uncovering the truth that suburbs are not necessarily safer than cities, crime is not getting "worse," and who is (and is not) the most common criminal.


TRICK OR TREAT

Yale economist Dean Karlan treats trick-or-treating as a behavioral science experiment, and comes to some startling conclusions...


BEST CHART COMIC OF THE WEEK
Source: xkcd

Friday, October 25, 2013

Data link roundup (week of October 25, 2013)

The week's top data analysis links...
This week's theme: beginnings, endings, and how we spend the time between.


BABY BOOM / BABY BUST

Washington, DC is having a mini baby boom. Japan is experiencing a massive baby bust.


LIFE EXPECTANCY

The United States may have a high standard of living, but U.S. life exepctancy has not been keeping pace with other nations.


WASTING TIME?

With the advent of modern technology, we are spending more time online, but there are still only 24 hours in a day. So what do we give up to spend time on social media?
Source: Harvard Business Review
If you guessed "work" or "sleep," you're right. Based on data from the American Time Use Survey, researchers at NBER found that:
...each minute of online leisure time is correlated with 0.29 fewer minutes on all other types of leisure, with about half of that coming from time spent watching TV and video, 0.05 minutes from (offline) socializing, 0.04 minutes from relaxing and thinking, and the balance from time spent at parties, attending cultural events, and listening to the radio. Each minute of online leisure is also correlated with 0.27 fewer minutes working, 0.12 fewer minutes sleeping, 0.10 fewer minutes in travel time, 0.07 fewer minutes in household activities, and 0.06 fewer minutes in educational activities.


BEST CHART VIDEO OF THE WEEK

The Economist explains why most published research is wrong...



IN CASE YOU MISSED IT...

Thursday, October 24, 2013

New post-shutdown release schedule for U.S. federal data

The federal agencies affected by the shutdown have published new release schedules for their data. Most releases are delayed by one to two weeks, some (including the American Community Survey Public Use Microdata files) are subject to a much longer delay...

For details, see:

Freaky facts and scary stats for Halloween 2013

TERRIFYING TREATS:

America's candy consumption in 2010 was nearly 25 pounds per person. If this candy were entirely Snickers bars, it would be the equivalent of nearly 4 candy bars, per week, per person. The volume of candy consumed, much like home prices, peaked in the middle of the decade, dipped at the start of the recession in 2008, and increased slowly each year since then.

American confectionery manufacturers produce about 35 million pounds of candy corn each year. That adds up to 9 billion candy corns - or about 30 kernels per person in the U.S.

For Halloween itself, Americans purchase nearly 600 million pounds of candy, spending nearly $2 billion for treats to hand out to trick-or-treaters.

Sources: U.S. Census Bureau, Current Industrial Reports, Confectionery: 2010National Confectioners AssociationDaily Infographic 2011 and 2012


HOME PRICE PREMIUM NEAR FINAL RESTING PLACE

According to Redfin (and contrary to what one might guess) homes near cemeteries sell for more, per square foot, than homes not near cemeteries.
"Redfin analyzed the price of homes less than 50 feet from a cemetery, and compared those to the price of homes less than 100, 200, 500 and 1,000 yards away. The numbers indicate that on average, homes near cemeteries are slightly smaller, but sell for more per square foot. On average, homes closest to cemeteries sold for $162 dollars per square foot, whereas the homes located more than 500 yards away sold for $145 per square foot."
But these homes were on the market for longer than their non-cemetery peers...


LITTLE GHOULS AND GOBLINS:

There were an estimated 41.1 million potential trick-or-treaters (children age 5-14*) in the United States in 2012, and 3.7 million in Canada.
Source: U.S. Census Bureau, Facts for Features and Statistics Canada Hallowe’en... by the numbers
*Note: Of course, many other children - older than 14, and younger than 5 - also go trick-or-treating.



IN THE PUMPKIN PATCH:

U.S. pumpkin production totaled 1.2 billion pounds, in 2012, with a value of $149 million. In that year 47,800 acres of farmland were under cultivation for pumpkins.

Six states are pumpkin hotspots: Illinois, California, New York, Ohio, Pennsylvania and Michigan each accounted for more than 100 million pounds of pumpkins grown in 2010.

In Canada, there were 7,027 acres of pumpkins patch in 2012, for production of more than 63,700 tonnes valued at $17.6 million.

Sources: USDA National Agricultural Statistics and Statistics Canada Hallowe’en... by the numbers


A BOOming INDUSTRY:

The average American adult will spend nearly $75 on decorations, costumes and candy, down a bit from $80 per person last year, according to the National Retail Federation.

Total Halloween spending is projected to be nearly $7 billion.
Source: National Retail Federation

Friday, October 18, 2013

Data link roundup (week of October 18, 2013)

The week's top data analysis links...


JUST IN TIME FOR HALLOWEEN

In an attempt to prove that statistics really are scary... This week UC Irvine kicked off a new class based on the AMC television show The Walking Dead.

The free MOOC uses the zombie apocalypse as a vehicle for explaining public health, social science, physics and mathematics.
(Thanks to my friend and colleague T.G. for letting me know about this class!)


BOOMERS NOT BOMBARDING DOWNTOWNS

Contrary to chatter in real estate circles, Baby Boomers are not flocking to urban areas. (Really, this is no surprise. Boomers have not been moving much, at all, since the housing market crash.)


QUALITY OF LIFE

Quality of life rankings evolve over time, as socially-important metrics, like death from typhoid (from the 1931 report "The Worst American State") give way to the amount of money spent on healthcare (from the 2013 Livability report), and the consumption of gasoline goes from a positive metric (1931) to a negative one (today).

But, sadly, not much has changed with respect to state quality of life rankings. From 1931 to present day, Mississippi lags the nation...


SHUTDOWN SHUTS DOWN

The employment report is delayed... Census surveys are behind schedule... but at least the U.S. government is again open for business. In final shutdown news... Richard Florida explores the geographic divides emerging in American politics.


BEST CHART COMIC OF THE WEEK

Because there are many important uses for Census data...
Source: xkcd

Friday, October 11, 2013

Data link roundup (week of October 11, 2013)

The week's top data analysis links...
This week's theme: What's going on in the nation's capitol.


WAS THERE AS MUCH GRIDLOCK THEN, TOO?

Since the Lincoln Memorial is closed, this is probably an appropriate time to mention that the site once was under water. Or, to be more precise, much of the National Mall is located on land that was formerly the Potomac River.
Source: Smithsonian Magazine
The Smithsonian has an online mapping tool (still working, despite the shutdown) that compares Washington, D.C. in 1851 and today.

The interactive mapping tool also showcases other cities, including New York, San Francisco, Chicago, Los Angeles, and more.


TO WHOM DO I OWE...?

Despite all the chatter about the impending debt ceiling, I suspect (from commentary overheard both on the news and on the subway) that most people have no idea to whom the U.S. government owes money. The debt data are readily available from the Government Accounting Office, and National Public Radio turned the information into an easy-to-read graphic.
Source: NPR
(PS - It is worth reading the GAO report, which explains the difference between debt held by the public and debt held by government accounts like the Social Security trust fund.)


WHAT THE SHUTDOWN LOOKS LIKE IN THE DISTRICT

  • Metro ridership is down 20 percent.
  • No survey data are being collected by agencies like the Bureau of Labor Statistics, Census Bureau, and U.S. Department of Agriculture.
  • CDC is not publishing any new Morbidity and Mortality Weekly Reports. The CDC website notes that "Because of the current lapse in government funding, MMWR is able to publish and distribute only reports on immediate health threats."
  • The Washington Post has been collecting, and mapping, stories from people affected by the shutdown. The interactive map is both fascinating and depressing.



BEST CHART OF THE WEEK

This chart is more than a week old. In fact, The Economist published a comparison of hospital costs by country way back in June, but given the rhetoric pouring off of Capitol Hill, perhaps it bears another look:
Source: The Economist
Yes, the average cost per hospital patient per day in the United States is more than $4,000, while nations like New Zealand, France, and Spain (among many others) have costs lower than $1,000 per patient per day (and longer life expectancy, too).


IN CASE YOU MISSED IT...

This blog's list of data resources to get you through the data-dark days of the U.S. federal shutdown received some nice praise from some well-respected authors:

Friday, October 4, 2013

Data link roundup (week of October 4, 2013)

The week's top data analysis links...


DARK DAYS FOR DATA

In addition to federal data websites going dark, the Bureau of Labor Statistics is delaying the jobs report that was due for release today because only 3 people are "exempt" from the shutdown furlough.

While the delay of September numbers is disappointing, staffing shortages (82 percent of Department of Labor workers, including nearly 100% of the BLS division, are on furlough) mean October numbers may not be collected at all.


CITIES MOST AFFECTED BY THE SHUTDOWN

According to numbers crunched by Brookings, Moody's Economy.com, and the Washington Post, seven metro areas have 10 percent or more of their workforce in federal or military jobs. Colorado Springs tops the list with nearly 19 percent federal workers (thanks, perhaps, to the Air Force Academy) followed by Virginia Beach, Honolulu, D.C., El Paso, Ogden, and San Diego.

Source: Washington Post
Important note: These figures include federal and military personnel, but do not include private-sector contractors to the federal government, who are also likely furloughed...


AGENCIES MOST AFFECTED BY THE SHUTDOWN

ABC News (among others) provides a detailed, department-by-department list of the estimated number of federal workers and percent furloughed due to the government shutdown. Some of the hardest hit include:

  • National Science Foundation (98.5 percent)
  • Department of Education (94 percent)
  • Environmental Protection Agency (96 percent)



BEST CHART CARTOON OF THE WEEK

It's sort of funny, and sort of sad...
Source


IN CASE YOU MISSED IT...

Tuesday, October 1, 2013

Where to go for data when the federal websites shut down

Because it looks like most federal websites will shut down when the government does... (update: Census website down as of 10:30am EST)

Here are some other helpful data resources, ranging from national to state and local downloads, to get you through any dark days with no federal data access:
You may also want to try the "Wayback Machine," an online archive of webpages. (It does work for the Census Bureau webpage as of September 2013.)

For state-specific data... here are links provided by readers and colleagues around the nation:

Check the Clearinghouse of SDCs for a comprehensive listing of Census State Data Centers, or refer to one of these state-based resources:
And here's a bit of 2012 American Community Survey data that may be helpful:
I also have data on U.S. fertility and birth rate by age back to the early 1900s... contact me if you'd like the file.

Please tweet me @DataGeekB or email me if you have recommendations to add to the list!

Special thanks to @SR_Spatial@MetroGram@CarlSchmertmann and @NDCompass for recommending several links. @PolicyMap also contacted me to let me know that they provide a wealth of data, some for free, some for a subscription fee.

Friday, September 27, 2013

Data link roundup (week of September 27, 2013)

The week's top data analysis links...
in honor of World Contraception Day.

FASCINATING FACTS ABOUT FERTILITY AND CONTRACEPTION

The Guttmacher Institute is always my go-to source for information about contraceptive use. In honor of World Contraception Day, here are some striking facts about contraceptive use in the United States:
  • Far more married women (77%) than never-married (42%) use contraception
  • 99% of US women (age 15-44 and who have ever had sex) have used at least 1 contraceptive method
  • Contraceptive use is common among women of all religious denominations, including:
    • Nearly 90 percent of Catholics and Protestant women (who are currently having sex but do not want to get pregnant) currently use a contraceptive method.
    • Among sexually experienced religious women, 99% of Catholics and Protestants have ever used some form of contraception.

UNINTENDED PREGNANCY

This map highlights states where unintended pregnancy rates are highest (Mississippi, Louisiana, California), and where annual public spending on unintended pregnancy exceeds $1 billion per year (in the states of California, Texas thanks, no doubt, to their large population size).

Source: Maps on the Web

PREMARITAL SEX, CONCEPTION, AND SHOTGUN MARRIAGES

Rising rates of premarital conception (and, likely, rising rates of premarital sex) accounted for the increasing number of premarital first births to women born between 1920 and 1949.

BUT for women born later (between 1945-64) increases in premarital first births were primarily attributable to declines in "shotgun marriages," according to new research published in the journal Demography.


BIRTHDATE MATTERS

In response to my post last week about the high frequency of August and September birthdays@DrDemography shared a great link... on how pregnancy due date may affect an infant's health. (For causality, think flu season...)


BEST CHART OF THE WEEK

Following on last week's theme about the frequency of birthdays, this infographic shows not only frequency by birth month, but also by day... 
Source: IPH79 on Tumblr with data from the NY Times


IN CASE YOU MISSED IT...

Friday, September 20, 2013

Data link roundup (week of September 20, 2013)

The week's top data analysis links...

POPULATION TRENDS

Late last week Slate published an excellent piece detailing the limits of longevity.

And speaking of longevity...
The Population Reference Bureau released the 2013 World Population Data Sheet and online interactive graphics.

Image source
And speaking of population growth...
The New York Times published an very non-Malthusian op-ed by Erle Ellis suggesting that there is no such thing as a "carrying capacity" for the earth.
(Thanks to @DrDemography for sharing the link.)

For what it's worth...
While I lean more toward Hans Rosling's "possibilist" attitude about population growth than toward Malthus' pessimist worldview, I also suspect Ellis has never seen the Star Trek episode The Trouble With Tribbles.

Also, on the blog Weeks Population, Dr. John Weeks published a succinct rejoinder to Ellis' op-ed.


IN CASE YOU MISSED IT...



Thursday, September 19, 2013

New data: 2012 American Community Survey

New data released today from the 2012 American Community Survey (and also from Tuesday's release of the Current Population Survey) show no change in median household income, poverty rate, and health insurance coverage in the United States (nor change across the majority of states in the U.S.).

While this may seem like a bad news story, 2012 is the first year since the the beginning of The Great Recession in which income did not fall and poverty did not rise. While the trends do not yet show growth, 2012 may be the inflection point the economy has been waiting for.

One key point of note, older Americans seem to be faring better - or at least recovering from the recession quicker - than younger Americans with substantially lower overall rates of poverty (despite a bit of an increase from last year for those age 65+) and improving homeownership rates.

For a concise summary of the new data:
William Frey, of Brookings, discusses findings from the 2012 ACS on Morning Edition. (Note: I love that reporter/interviewer Steve Inskeep refers to today's data release as "Christmas for demographers.")

Wednesday, September 18, 2013

(Not so) Popular opinion on population forecasting?

This week the myopic Globe and Mail reporters seem to think that if we cannot predict the population 50 years from now with complete certainty, we might as well hang up our hats and just stop trying.

Really?
That's their solution? Just quit. Ignore all data. Ignore all trends. Live like we don't have vital events registries and calculators, much less computers? I wonder if we should stop trying to predict the path of hurricanes, too, because, you know, we can't tell exactly where the eye will make landfall?

I'm flabbergasted by the implication that someone would prefer no information at all to a well-informed range of possibile outcomes. At first, I thought the article by Philip Cross must be an Onion link that I was mis-reading.

(I'll spare you the full force of my rant. Just envision a demographer unleashing a stream of profanities about willfully ignorant writers...)

What infuriates me most, I think, is the final paragraph wherein Cross writes:
"In the future, if the UN or Statcan insists on producing forecasts of population or the labour force, they should be obliged to include an easily-understood summary comparing their past forecasts and the actual outcomes, so people can assess for themselves the credibility of these exercises. It would also force statisticians and modellers to confront the flaws in their forecasts, something they seem blissfully unaware of and unaccountable for."
Perhaps Cross is blissfully unaware of the volumes and volumes of data, analysis, conference presentations, and peer-reviewed journal articles produced by demographers (including Stanley Smith , Jeff Tayman, David Swanson, Stefan Rayer, to name just a few) documenting exactly that: forecast error and forecast accuracy.

We demographers are not the ones who are blissfully unaware. In fact, there is an entire branch of demography devoted to improving forecasting techniques and measuring accuracy and error!

Cross, however, is blissfully unaware. Perhaps he should stop throwing stones until he moves out of his glass house.

Saturday, September 14, 2013

Why is September a common birthday month?

Note: This post is adapted from last year's post and includes new data and analysis...

Do you feel like you're spending a small fortune on birthday cards every September? Is your Facebook feed alight with birthday reminders this month? Have you noticed more birthday party invitations arriving in the mail in recent weeks?

If you have noticed a spike, you are not alone. There is a clear pattern of "birth seasonality" resulting from a "seasonal cycle in fecundability" documented in the scientific literature. Holidays and long winter nights are partly to blame for more birthdays in September, but human biology is at work as well.

In short, in the northern hemisphere, women are more likely to get pregnant in late fall and early winter than at other times of the year. As a result more births occur late summer and early autumn, a trend displayed clearly in the chart below with birth data from the United States in 2010 and 2011. (Note: In the southern hemisphere, the seasonal peak occurs about 6 months earlier.)
Source: U.S. Centers for Disease Control and Prevention and author's calculations
In the chart above, you may notice that March 2010 births appear high, but consider that February is a short month, and March is a 31-day month. August also has more days than neighboring month, September.

To correct for this, we can estimate the average number of births per day of the month. With this adjustment the seasonal pattern becomes even more pronounced.
Source: U.S. Centers for Disease Control and Prevention and author's calculations
Correcting for the number of days per month shows September as the clear leader for births in 2010, as it is in most years. But 2011 shows a slightly different pattern - August leads September by about 75 births per day.

The lower number of births in September 2011 may, or may not, be a consequence of a massive blizzard that shut down transportation along much of the east coast in December 2010...

Friday, September 13, 2013

Data link roundup: Higher Ed (week of September 13, 2013)

The week's top data analysis links...
This week's theme: Higher ed, higher earnings?


RETURNS TO EDUCATION

That higher education leads to higher pay is a belief so fundamental to public policy and private decision-making that it's rarely questioned. And, indeed, on average higher levels of education correlate with higher employment and earnings levels (at least according to the latest data from the U.S. Census Bureau).

But is all education created equal? Does a higher degree always lead to a bigger paycheck? Indeed, the story is more complex...

First, The Economist explains why it doesn't (always) pay to get a Ph.D.

Second, this week analysis published by Anthony Carnevale, an economist at Georgetown University, shows that not all majors are created the same (at least not in earnings potential).

Graphic source: National Public Radio

DEMOGRAPHICS OF THE GRADUATING CLASS OF 2013...

Child Trends published a summary of the demographic and socio-economic characteristics of the high school graduating class of 2013. Highlights include:

  • 89 percent are covered by health insurance
  • Nearly three quarters have experienced physical assault
  • 68 percent will go on to college
  • 35 percent volunteered at some point during the year
  • Less than half get the recommended amount of physical activity
  • 20 percent watch 4 or more hours of television per weekday



IN CASE YOU MISSED IT...


BEST CHART COMIC OF THE WEEK
Source: Picking a college major XKCD


Friday, August 30, 2013

Data link roundup - visualize it (week of August 30, 2013)

The week's top data analysis links...
This week's theme: data visualization (overused term, but an important concept)


VISUALIZATION TOOLS

Over the past few weeks I've been working on data visualizations for a project at my day job. For prior projects, I had been using the "motion charts" Google gadget to make interactive graphics, but that tool (sadly) has been disabled.

In my search for a replacement, I learned about a wide variety of free online data visualization tools. A few resources worth noting are: Weave, Tableau, and Datawrapper. All three allow users to develop interactive charts and graphs. Tableau and Weave also offer mapping capabilities.

And if those options still don't fit your needs, try this directory of about a dozen other tools worth further exploration.


VISUAL EXPLORATION OF DATA

Sinan Aral's article in Harvard Business Review explains how the New York Times uses visual representations of data to understand patterns that a simple table might not illuminate...



BEST CHART OF THE WEEK

I'm a fan of images that convey a wealth of information with a simple concept. Population-adjusted country size maps, when done well, can do just that...

Source: Gizmodo


Friday, August 23, 2013

Data link roundup (week of August 23, 2013)

The week's top data analysis links...


RANDOM BITS


IN CASE YOU MISSED IT...


BEST CHART COMIC OF THE WEEK

For those of you preparing for the Fall 2013 semester...
Source: PhD Comics

Thursday, August 22, 2013

Odds for betting on a birthday

Earlier today I tweeted about my maternity leave memo...
My maternity leave memo made finance staff laugh. What? Don't all moms incl a table w/ statistical likelihood of birth by week of gestation?
— Beth J (@DataGeekB)
The tweet generated as much commentary (and laughter) as the memo did, so here are some highlights of the data and answers to reader questions.

While plenty of practitioners will tell you that a "full term" birth is considered to be 40* weeks (280 days) of gestational age, the numbers simply don't bear that out. In recent years, both the median and the mode place a baby's most likely birth date at week 39 with a standard deviation of 7 to 9 days (depending on the source).
Source: CDC Births: Final Data for 2011, compiled by author
Note: Data shown here are for singleton births only, as multiple births have a higher likelihood of preterm delivery
I suspect the misconception about the most common length of pregnancy is a matter of old data.

In 1990 the median delivery date for a singleton** birth was in the 39th week, but the mode was 40. Perhaps most shockingly, in 1990 more than 10 percent of births occurred at 42 weeks or later!

Birth timing is not entirely predicted by biology. Medical interventions abound, as one in three singleton births are via cesarean delivery, so the distribution of births by gestational age is highly influenced by current medical standards.

Research from the mid-2000s suggests that mothers and infants are at higher risk of birth complications if pregnancy is allowed to extend beyond 42 weeks, so current practices encourage the use of medical interventions to ensure delivery before 42 weeks. This likely explains the substantial drop in post-term births between 1990 and 2011.

The data: Distribution of singleton births by gestational age
2011 2010 2006 2005 2000 1990
Under 28 weeks 0.6% 0.6% 0.6% 0.6% 0.6% 0.6%
28-31 weeks 1.0% 1.0% 1.0% 1.0% 1.0% 1.1%
32-33 weeks 1.2% 1.2% 1.3% 1.3% 1.2% 1.2%
34-36 weeks 7.3% 7.5% 8.1% 8.1% 7.3% 6.8%
37-38 weeks 25.7% 26.7% 28.9% 28.3% 24.4% 19.4%
39 weeks 30.1% 29.1% 26.2% 26.0% 24.9% 22.0%
40 weeks 19.9% 19.7% 19.4% 19.8% 21.9% 23.0%
41 weeks 8.6% 8.5% 8.6% 8.9% 11.3% 14.4%
42+ weeks 5.7% 5.6% 5.8% 6.0% 7.5% 11.5%
Source: CDC, National Vital Statistics Reports, Births: Final Data for 2011

Keep these stats in mind the next time you're betting in an office "guess the birth date" pool.

Have questions about the data?
Send me a message!


NOTES:
*Births prior to 37 weeks are considered to be pre-term (or premature). Births at or after 42 weeks are considered to be post-term. The wide range in the middle, from 37 to 42 weeks, truly reflects full-term gestation.

**Singleton births are births to an individual child, and excludes twins, triplets, or other multiple births.

Friday, August 16, 2013

Painfully obvious research results - data link roundup (week of August 16, 2013)

The week's top data analysis links...
This week's theme: The Duh Files.

Did we really need a study to "know" this?


BIRTH CONTROL BLUNDERS

Culling statistics from the National Survey of Family Growth, researchers found that the "withdrawal" or "pull-out" method of birth control is surprisingly common. 31 percent of surveyed women used withdrawal as a form of birth control at least once.

But (not surprisingly) the method is terribly ineffective. Unintended pregnancy rates were 21 percent among those who used the withdrawal method.

In an interview published by the National Institutes of Health, study author Dr. Annie Dude notes:
"Our study showed that use of withdrawal for contraception is very common, but it doesn't work as well as other methods"
The full study will be published in the September issue of Obstetrics & Gynecology.


RUNNING IN HEELS

New analysis published in the Research Journal of Applied Sciences, Engineering and Technology shows that when running in heels, energy expenditure increases with heel height... at least for the dozen women who participated in the study.

No word on the effects of heel high on the risk of breaking an ankle...


AND THERE'S MORE...

And other entries into the "painfully obvious results of research studies" category:


Now don't get me wrong, I'd much rather see silly, and seemingly painfully obvious correlations than paid-for-by-the-producer clinical trials that later are proven to be flawed, or research that shows a strong correlation and jumps to the conclusion that correlation means causation (when, in fact, confounding factors are to blame).

And we all know that most of these studies include findings that are deeper, more complex, and more useful than the titles imply.

For example, the University of Georgia's findings that abstinence only education does not work at reducing teen sexual behavior or teen pregnancy seems obvious. Well... it seems obvious to most of us, but some public policy decisions would benefit from wider distribution of the the evidence.

Then again, sometimes it's just fun to wonder what on earth the researcher was thinking (and how on earth the project got funded).

And really, did we need the BMJ to publish an article to know that sword swallowing is a dangerous profession???

Friday, August 2, 2013

Data link roundup (week of August 2, 2013)

The week's top data analysis links...
Last week we focused on mortality stats, so this week we're looking at the other end of the life course spectrum: babies and mommies.


PAMPERING A BABY (not as easy for some families)

New research published in the journal Pediatrics reveals a harsh reality for low-income families: diapers cost more than many low-income families can afford.

Lack of adequate diaper supply can result in negative outcomes for caretakers and children, including: family stress, anxiety, depression, and child health problems (e.g. increased risk of urinary tract infection).

Data were...
...derived from a cross-sectional study in 877 pregnant and parenting women. Mothers completed surveys on topics related to mental health, basic needs, and health care use. Logistic regression was used to estimate the relationship between diaper need and psychosocial correlates.
The study found that nearly one third of mothers in the survey reported a diaper shortfall. Hispanic women were significantly more likely to report diaper need than African American women.

(See also: diaper report summary on The Atlantic CITIES)


BREASTFEEDING BY THE NUMBERS

Breastfeeding rates have been climbing slowly but steadily for the past several years, according to new data released by CDC.

Rates of breastfeeding at 6 months are highest in Idaho, California, and Oregon according to the CDC's 2013 Breastfeeding Report Card. Rates in those three states exceed 70 percent. Rates are lowest, below 20 percent, in Mississippi.


SEX SELECTION AT BIRTH

New analysis from PRB highlights the problem of son-preference sex selection at birth in Armenia, Azerbaijan, and Georgia,


BEST CHART OF THE WEEK

Partly based on fertility and mortality trends, completely based on the latest United Nations population projections, The amazing, surprising, Africa-drive demographic future of the Earth, in 9 charts is worth a look.

Here is a sample (1 of the 9 interactive graphics):

Source: Max Fisher, Washington Post


IN CASE YOU MISSED IT...

Friday, July 26, 2013

Data link roundup (week of July 26, 2013)

The week's top data analysis links...
This week's theme: we are mere mortals...


... MORE LIKELY THAN BEING STRUCK BY LIGHTNING

Risk of death from a lightning strike has declined in the U.S. (though men still face higher risk of death by lightning than women do) according to data from CDC.

But injuries and hospitalizations from distracted walking are on the rise. (Insert punch line about how people can't walk and talk at the same time...)


THE CITY IS SAFER

While crime rates tend to be higher in urban areas than in rural ones, accidental injuries and death (mostly from automobile accidents) are considerably higher in rural areas than in urban ones -- so much higher, in fact, that cities are actually "safer," from a mortality risk perspective.

As Emily Badger writes in The Atlantic CITIES:
Yes, homicide-related death rates are significantly higher in urban parts of the country. But that risk is far outweighed by the fact that you're about twice as likely to die in a car crash in rural America than you are in the most urban counties. Nationwide, the rate of "unintentional-injury death" – car crashes, drownings, falls, machinery accidents and the like – is about 15 times the rate of homicide death. Add together all the ways in which you might die prematurely by intentional or unintentional injury (as opposed to illness), and your risk of death is actually about 22 percent higher in the most rural counties in America than in the most urban ones.
The full report "Safety in Numbers: Are Major Cities the Safest Places in the United States?" is published in the Annals of Emergency Medicine.

Note: Also, as Emile Durkheim noted many decades ago, deaths from suicide also follow measurable social and demographic patterns. More dense urban areas tend to have lower rates of suicide than less dense rural areas do.


JUST FOR FUN

Ice cream consumption is strongly correlated with murder, and other ridiculous correlations (via Buzzfeed).


BEST CHART OF THE WEEK

Quite possibly the best example that correlation does NOT equal causation:

Source: Bad Psychology



IN CASE YOU MISSED IT...


Friday, July 19, 2013

Data link roundup (week of July 19, 2013)

The week's top data analysis links...
This week's theme: Maps! Cartography! GIS!


HOW NOT TO MAP YOUR DATA

While generally one of my favorite daily reads, The Atlantic WIRE gets their map analysis of murders in America all wrong.
Source: The Atlantic WIRE
The problem?

TAW maps total number of murders, but does not control for population size, and then highlights that California and Florida are always at the top of the list.

News flash to the murder map analysts: Those are two of the nation's most populous states!

Is it any wonder that California is always highest, followed by Texas, Florida, and New York? At this stage in the cartography game, we shouldn't have to say this, but when comparing trends by state:

Map per capita, people!
Per capita!



HOW DIVERSE IS YOUR CITY?

Starting with the 2000 Census, Eric Fischer developed a series of dot-density maps to display racial distribution patterns within U.S. metropolitan areas. Fisher updated the demographic dot map series for the 2010 Census.
Source: Eric Fischer

AFFORDABILITY: HOUSING AND TRANSPORTATION

The two largest components of the average American household budget are: housing and transportation, but most analysis focuses on just the housing part of "affordability" when comparing U.S. metro areas. The H + T index combines both in a web-based mapping application.
(Thanks to MC for passing this link along!)


JUST FOR FUN

And a few maps just for fun...



BEST CHART VISUALIZATION TOOL OF THE WEEK

Special thanks to my friend RC for pointing me to the Urban Observatory, an online visualization tool that allows users to compare socio-economic and environmental characteristics quickly across major world cities. Take, for example, population density in New York, Tokyo, and Mumbai...
Source: Urban Observatory


IN CASE YOU MISSED IT...

Now that Google Reader is gone, if you're not following on Twitter, you should be. I post fact-checked links and interesting data insights (nearly) every day.