Life goes on, and so does life expectancy

/ bs king / 3 Comments

Life expectancy is a funny thing.  It’s a pretty often quoted statistic that not many people realize is just that – a statistic.  It’s also fairly misunderstood, in that many people presume it’s static.

Truthfully, your life expectancy changes over the course of your life based on how long you’ve already lived. Most people accept this as making sense once it’s pointed out, but it’s not often the first thought people have when they here it (and journalist’s are ABYSMAL at clarifying the “at birth” part of most life expectancy estimates).  Anyway, this week chartporn.org posted this chart, which I think illustrates the changes nicely.  I didn’t check all the other data they put on there (though I was surprised to see how low the median age for first divorces is), but I thought the overall affect was quite informative.

In particular, I like the beginning of the chart, where it shows that if you make it beyond your first year, you actually get a bump up pretty quickly.  Infant mortality is not often thought of as affecting overall life expectancy in developed countries, but it does.

Friday Fun Links 6-22-12

/ bs king / 1 Comment

Why ignorance shouldn’t be a dirty word.

I think this article’s premise should be someone’s doctoral thesis.
I’ve never used Pinterest, but this version of it seems to have potential.

Work got you down?  Don’t try robbing banks.  It’s not as lucrative as it would seem.

Since that’s out, perhaps you should go on a road trip.  Weather.com has a trip planner that will show you weather for your route.

This may not be as interesting to you as it is to me at the moment, but Chris Mulligan put up this very cool graph of birth trends by day of the year:

It looks like the data used is from 1969 to 1988….I would have loved to see this graph for 100 years ago, before there were any c-sections or inducements to contend with.  I had a Coptic Egyptian roommate at one point, and she told me that when she was little, they couldn’t divide up kids by birth date when they went to sort people out.  Apparently Coptic’s are prohibited from having sex for almost 170 days out of the year, and so the babies are all born very clustered together (9 months after the end of Lent for example).  I’d imagine the data would be nearly impossible to get a hold of, but I’d love to see some cultural variations on this to see how things correlated with social norms.

More thoughts on the soda ban

/ bs king / 1 Comment

Yesterday I found out the soda ban is potentially hitting a bit closer to home.

For those of you not familiar with Cambridge, MA, it’s affectionately known as “The People’s Republic” (and even has a communist bar of the same name).  Thus the proposed ban was pretty unsurprising.

Coincidentally, Ben Goldacre put up a new post yesterday publicizing a paper he coauthored to try to push governments in the UK to actually conduct trials of their policies before implementing them.

Best quote:

We also show that policy people need to have a little humility, and accept that they don’t necessarily know if their great new idea really will achieve its stated objectives. We do this using examples of policies which should have been great in principle, but turned out to be actively harmful when they were finally tested.

Contrast this to the Mayor of Cambridge’s statement on the soda ban:

“As much free will as you can have in a society is a good idea,” Davis said Tuesday. “… But with a public health issue, you look at those things that are dangerous for people, that need government regulation.”

Is no one interested in finding out if this idea will actually work before implementing it?  The leading researchers in the field seem to think it won’t.   I tend to agree with them.  You know what though?  I’m game.  Let’s put it to a randomized trial.  There are those who think the constitutionality of this should be worked out first, but I think a well run trial could open the door for an opt in system rather than a mandatory one.

Hey, maybe if politicians stayed a little more open to testing their ideas, you wouldn’t wind up with cartoons like this one:

Quote of the Week

/ bs king

Another thing I must point out is that you cannot prove a vague theory wrong. If the guess that you make is poorly expressed and rather vague, and the method that you use for figuring out the consequences is a little vague – you are not sure, and you say, ‘I think everything’s right because it’s all due to so and so, and such and such do this and that more or less, and I can sort of explain how this works’…then you see that this theory is good, because it cannot be proved wrong! Also if the process of computing the consequences is indefinite, then with a little skill any experimental results can be made to look like the expected consequences.                                      -Richard Feynman                                                                                                          “The Character of Physical Law”  1992  pp.158-159

I feel this quote should be a mandatory back drop for every political speech given, especially in election years.

Does race or profession affect sleep?

/ bs king / 3 Comments

I’ve commented before on my skepticism about self reported sleep studies.

Two recent studies on sleep piqued my interest, and while my original criticisms hold, there was yet another issue I wanted to bring up.

The first was from a few months back at the NYT blog, commenting on the most sleep deprived professions.
The second is from Time magazine, and talks about sleep differences among the races.

My gripe with both studies is the extremely small difference between the rankings.

In the professions study (sponsored by Sleepy’s btw), the most sleep deprived profession (home health aide) clocks in at 6hr57m.  The most well rested is loggers, with 7h20m.   On a self reported survey, how significant is 23 minutes?

From the study on races:

Overall, the researchers found, blacks, Hispanics and Asians slept less than whites. Blacks got 6.8 hours of sleep a night on average, compared with 6.9 hours for Hispanics and Asians, and 7.4 hours a night for whites. 

Here we see the same thing….there’s a 6 minute difference between the totals for Blacks and Hispanics and Asians.   Whites get 30 minutes more than Hispanics/Asians and 36 minutes more than blacks.

I question the significance of this, since I can’t remember whether I went to bed at 9:00 or 9:30 last night, and would have to guess if someone asked me.  Both surveys state this was self reported, and thus the chance these averages could be even closer together is huge.

Additionally, these differences do not actually reach the level of significance that the studies showing the dangers of sleep deprivation reach.

For example, in this study about sleep and overeating, subjects were woken up 2/3rds of the way through their normal sleep time.  That would be 2 hours early for nearly everyone above.  The studies on heart disease were only linked with chronic insomnia.  Cancer and diabetes are both more common in shift workers, but as someone who worked overnights for 3 years, I can tell you that’s not the same as waking up 30 minutes early.

Kaiser Fung has a great post about the popularizing of tiny effects that will be a hit if you didn’t like Freakonomics.

Stats and Father’s and Father’s Day Stats

/ bs king / 5 Comments

I spent most of yesterday driving back from somewhere on the Pennsylvania/Maryland/West Virginia border, so I didn’t have time to do a proper Father’s Day post.  I did call my dad though, so I guess I get half credit.

I wanted to do a post for my father, because he’s pretty responsible for my love of stats.  If someone uncovers a stats gene some day, I got that from him too.  He’s the only other person I know who truly finds numbers and stats a great way to unwind.  He’s also the first person who I ever remember telling me to be more careful about how I read research.
As I recall, I was probably about 13 or 14, and someone had just told me that those from lower socioeconomic classes tended to score lower on the SATs.  I repeatedly this to my father, as I was outraged as only a teenage girl can be.  My father stopped me immediately and started explaining to me that socioeconomic status is not random, and therefore this may not be as bad as it looked.  College educated people would be likely to earn more and to also have children more likely to perform well on the SATs.  Whether this was a product of genetics or a general household emphasis, both nature and nurture would likely be stacked in favor of higher incomes.  We then had a nice long talk about school districts and testing bias, but he cautioned me strongly to remember that even if those situations were made perfectly equitable, higher income kids would like still score higher.  
It’s not often that a single conversation changes your outlook so completely, but that one did.  Here we are a decade and a half later, and looking for faults in studies is still a good chunk of what goes through my head on a daily basis.  Luckily for me, I had lots of people in my life who valued truth and intellectual integrity over agenda, but my dad is the first one I remember pushing this in a way that stuck.  
My Dad is the best example I have of someone who would actually repeat or acknowledge research that contradicted his own personal beliefs.  He taught us that a win doesn’t count if you have to distort the truth to get there.  I am eternally grateful for my Dad, and all the things he added to my life, statistically and otherwise.
To show my thanks, Dad, here are some numbers for you:

These show how important it is to have a dad.  
This is some census data about dads in America.
Here’s a link to the Sabermetrics for the current Red Sox team.

So happy Father’s Day dad, I sincerely hope that your emotional and mental state were at least one standard deviation above the median on a normalized scale.  Preferably two, even when adjusted for weekend vs weekday averages.

Soda bans and research misapplications

/ bs king / 3 Comments

When I first read about Mayor Bloomberg’s proposed soda restrictions for NYC, I immediately thought of this post where I mentioned the utter failure of removing vending machines from schools.  Thus, I was extremely skeptical that this ban would work at all, and it seemed quite an intrusion in to private business for what I saw as an untested theory.

To be honest, I didn’t put much more thought in to it.  I saw the studies about people eating more from large containers floating around, but I dismissed on the basis that (like with the vending machine theory) they were skipping a crucial step.  Even if this ban got people to drink less soda, that doesn’t actually prove it would reduce obesity.  You have to prove all the steps in the series to prove the conclusion.

A few days ago, the authors of the “bigger containers cause people to eat more” study published their own rebuttal to the ban.  In an excellent example of the clash of politics and research, they claim that to apply their work on portion sizes in this manor is a misreading of the body of their work.  They highlight that the larger containers study was done by assigning portion sizes at random, to subjects who had no expectations as to what they would be getting.  In their words, the ban is a problem because (highlight mine):

Banning larger sizes is a visible and controversial idea. If it fails, no one will trust that the next big — and perhaps better — idea will work, because “Look what happened in New York City.” It poisons the water for ideas that may have more potential.

Second, 150 years of research in food economics tells us that people get what they want. Someone who buys a 32-ounce soft drink wants a 32-ounce soft drink. He or she will go to a place that offers fountain refills, or buy two. If the people who want them don’t have much money, they might cut back on fruits or vegetables or a bit of their family meal budget.

In essence, by removing the random element and forcibly replacing what people want with something the don’t, you frequently will have the worst possible effect: rebellion.

Mindless eating can be a problem, but rebellious eating is even worse.

When the researchers you’re trying to use to back yourself up start protesting your policies, you know you got it all wrong.

It’s all (culturally) relative

/ bs king

Last week I put up a post regarding a study on sexism levels in men whose wives stay at home.  I argued that due to the diversity of that group of men, and the variety of reasons a woman might stay home, this study was essentially meaningless.

Another issue came up in the comments section that I wanted to touch on: cultural relevance of data.

Most studies that get press here in the US are from the US, performed on American subjects.  This is sketchy business.

In the study about stay at home moms, mothers who worked part time were lumped in with the stay at home mothers.  Interestingly, in the Netherlands, this would actually be 90% of the women.  Does that mean that nearly every Dutch man married to a woman is more likely to be sexist?  Or does it mean that part time work has different value in different cultures?

I took a look around for some other examples, and found that in China, many women see working as part of a new found freedom.  At a conference I attended a few months ago, I talked to a man from Shanghai who mentioned that his wife went back to work because she couldn’t have handled trying to fight off the two grandmother’s, both of whom wanted to watch the child.  Due to the one child policy, this was the only chance they would get to have a grandbaby.  In many ways, it was actually the hierarchical/patriarchal culture there that pushed his wife to go back to work, as opposed to having her stay home.  

As the world continues to flatten out, and as America continues to welcome new immigrants, we must be conscious of who studies are actually looking at and how generalizable the results are.  In the sexism study, even the authors admitted their findings were meant to be a commentary on the US only….but it should raise some questions that they seemed to be chasing after a structure that doesn’t exist in some very liberal countries.

Something to consider, depending on the goal of the study.

How long do you study to become one of the cultural elite?

/ bs king / 6 Comments

I took one class on assessment in my master’s, and it gave me a whole new respect for teachers (or anyone who routinely prepares questionnaires for people).

Figuring out how to assess whatever topic you’re assessing is really really hard.

That being said, I found this quiz particularly interesting.  It’s called “Do You Live In a Bubble?”, but it’s target is particularly the “new upper class” and how much they do or do not understand about the lives of most Americans.

What he chose to assess is fairly interesting….people you know, where you’ve lived, smoking and drinking patterns, jobs you’ve had, knowledge of popular media, etc.  Lots of interesting issues to be taken with those categories, especially for those who clearly didn’t get the score they were hoping for.  The comments are pretty amusing actually…I feel like one of the questions should have been “is it important to you that this quiz tell you that you are “of the people”?

The most interesting point here was actually the entire purpose of the quiz.  The author of the quiz answered a few follow up questions, but I thought this was the most telling one:

2. Do you feel that people scoring higher on the quiz are not culturally sequestered as well? 

Question from Reddit: HillbillyThinkTank[S]: “You’re right that everyone lives in a bubble of some kind; the tendency to cluster with similarly situated people is not a behavior limited to the “elite.” The way the quiz is structured, he is suggesting that a low-scoring person is culturally sequestered in a way that a high scoring person is not. I don’t think I agree with that.” 

Sure, they’re sequestered. We all live in bubbles of one kind or another. The problem is an asymmetry. As I put it in the book, it isn’t a problem if a truck driver doesn’t understand the priorities of a Yale law professor, or news anchor, or cabinet secretary. It’s a problem if the ignorance is the other way around, because the elites are busily affecting the lives of everyone else. When they haven’t the slightest idea what the rhythms and feel of life are like in mainstream America, they tend to make mistakes.

I thought this was an interesting case of trying measure a very abstract concept through concrete questioning.  He includes an explanation of each question and why it was included.

Agree or not with his questions, it certainly succeeds at being provocative.

Also, in case you’re curious, I scored a 56.