Correlation vs. casuality, divorce rate, and so on

I'm having one of my "tutees" (the opposite of tutor.  Yes, I know that tutee is not a word) read Malcolm Gladwell.  Gladwell writes about interesting subjects and cites some fascinating studies, but his logic is often off, especially when it comes to correlation vs. causality.  I mean, I will probably buy his book again just because it's entertaining, but I'll take his conclusions with a grain of salt. 

For instance, he writes that the reason why Asian cultures tend to emphasize hard work and persistence is because of rice cultivation, since it takes significantly more effort to cultivate rice compared to wheat.  He connects this with higher scores in standardized math tests;  Students from Korea, Japan, Hong Kong, and China score higher on these tests because they work harder, or so he concludes. 

Now, I'm not arguing that Gladwell is necessarily wrong, but I can't help but to point out that all this is merely a correlation, and he has yet to show reasonable causality.  And to be even more honest, it isn't even a strong correlation.  Rice cultivation began in China and is practiced in many other cultures outside of East Asia.  Thailand, for example, is the number 1 rice exporter in the world and rice has been a major staple for years and years.  But do you ever hear about Thais and their above and beyond work ethic?  I haven't.  What about Filipinos and persistence?  They eat rice too.  Or was Gladwell just talking about short grain rice?

Plus, I can't help but to notice that Korea and Japan were heavily influenced by Sinic (Chinese) culture for thousands of years.  May be it's not rice but Confucianism - there is a strong correlation between East Asian cultures and its connection to Confucianism, isn't there?  May be it's the writing.  Koreans and Japanese all borrowed Chinese Characters and used them for thousands of years, and it takes significantly more effort to learn Chinese Characters compared to Western alphabet.  May be it's the fact that the three countries all used "standardized test" to pick government officials, so they had to memorize and study harder.  May be it's that they are all located near the Pacific Ocean (okay, probably not)...

I'm not completely ruling out the theory, but there are at least thousand other correlations besides rice cultivation between the countries, yet why would you just point to rice and only rice?  And connecting this to the standardized testing has its own problems.  Without doubt, more hours in school and more practice will definitely higher standardized test scores.  But is that the only reason?  Will all standardized test scores be statistically same if all the nations had the same amount of school hours?  Who knows, may be it also has to do with IQ.  Studies have shown, albeit with much controversy, that East Asians (Korean, Japanese, and Chinese) often have slightly higher IQs than other races and cultures.  Or may be it's due to the East Asian teaching methods, where teachers put zero emphasis on factors such as team work and creativity, and do nothing but drills and drills over and over again.  May be such methods are more efficient for standardized testing.  Both IQ and teaching methods have little to do with hard work and persistence, and even less to do with rice cultivation.  Although I can't completely rule out the possibility, I can't single it out as the main cause either.

Now, Steven Levitt shows how to determine causality in his book, Freakonomics.  During the 80's the crime rate was sharply rising and nearly all the experts in the country predicted that crime rates will continue to rise well into the 90's and so on.  But during the late 80's and 90's, the crime rate took an unexpected turn and fell sharply.  The experts scrambled to find the right reason, often citing factors such as tougher gun laws, strong economy, aging of the populations, and so on.  But none of them, not even a single one, cited the most important reason: abortion. 

Levitt argues in Freakonomics that crime rates in America fell during the 90's because of abortion and couple other factors.  Aborted babies tend to come from less fortunate families whose parents do not have the ability to properly care for the baby, and fewer neglected babies lead to less criminals of the future.  So the (unfortunate) conclusion from Levitt is, legalizing abortion lead to the drop in crime during the 90's in America. 

Now the question is, how do you show that this isn't simply a correlation but a causality?  Levitt does this in an ingenious way.  He compares the crime data in the five states where abortion was made legal two years before Roe V. Wade (1973) and needless to say, the five states' crime rate begins to fall exactly two years before every other states.  But that alone, obviously, isn't enough to show causality.  Another way to go about this is by comparing abortion rates among states and their drop in crime.  Even after adjusted for many other factors, such as income levels, number of police, and level of incarceration, states with highest abortion rates experienced greatest dip in crime rates, and vice versa.  There are even more indicators.  A closer look at the data shows that crime rates amongst younger criminals fell drastically during the time period, while the crime rate among the older criminals did not change much.  Even studies from overseas have yielded similar results. 

This, to me at least, is a reasonable evidence.  There is a chance that all this is due to a sheer dumb luck and the true cause of the drop in crime rate is the lining of the stars.  But then again, there is also a chance that I might shag Kiera Knightley tomorrow night, here in Hong-Cheon, South Korea. 



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Cause of Divorce


All this reminds me of my friend in college, and the discussion that she had in her class.  She told me, in a matter-of-a-fact way, that higher income amongst women causes higher divorce rates.  When I asked her why she (or her professor) thought that way, she simply said, "Women in Orange County have higher income than the rest of the State, and they also have higher divorce rate." 

At this point, I just didn't say anything, because I was really annoyed, and I wanted to avoid confrontation.  I will give her credit - women with higher income might be the cause of higher divorce rates - but she obviously failed in providing enough evidences to show causality.  It feels right and seems right, obviously, to say that women with higher income are more independent and therefore are more free to divorce their husbands.  But you will need more than a simple correlation to convince me. 

Couple years ago, there was a period when I went around asking question about sustaining a marriage, in addition to attending church discussions abut marriage.  I guess watching Sharon and Albert get married, along with a few other couples, really sparked my interest.  But to my dismay, so many people just had "feel good" type of answers.  For instance, many people said that the trick to sustaining a marriage was patience.  But I couldn't help to point out that my father is one of the most impatient people that I know, yet my parents weren't divorced.  Plus, I highly doubt that all married people are patient, because I know that they are not.  What about caring?  Well, of course you want to care something about the person you're married to, even if it's just money.  Stating the obvious is like stating nothing and it's often insulting to the listener.  


I guess I got sick of people evaluating marriage in a qualitative way. 

"Yes, what you need in marriage is love, caring, sharing, patience, and respect for each other."

What does that mean?  Nothing, to me at least.  It's like saying, "My fantastic, marvelous car has an engine, with four black tires.  It's in a fabulous condition; overall a spectacular ride with windows."

Well, at least I know that it has tires.  Black tires.
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The "feel-good" type of answers are everywhere:  Why did the stock prices go down today?  because of the rising oil prices... even though there are at least hundred other probablecauses.  Such answers usually involve correlation pampered to look like science and qualitative words.

Yet another self-improvement scheme

This used to be my belief:  It's not that I don't have time, it's just that I can't manage it.  I can't manage my time well because I'm always too damn tired. 

So I made a little list of what I ought to be doing.  Why should I do these things?  I don't know, but I feel compelled to do them, to "improve" myself:

I want to...

   read a book a week (at least 1 hour a day)
   become a better writer (2 hours a day)
   learn Mongolian (2 hours a day)
   study for korean/english test (2 hours, either TOPIK, GRE or TOFEL/TEPs)
   become a better cook (1 hour a day - hey I gotta eat what I make)
   practice music (1 hour a day)
   take pictures/ edit pictures (1 hour a day)
   exercise (1 hour a day)

Total: 11 hours a day.  

Given that I have a full time job and two (sorta) part time jobs, this confirms that I literally don't have the time to do everything that I want.  It's 5 after work, and I go to sleep at 12.  And if you consider one hour of extra work at home (it's usually more) and two hours of skyping a day, this means I have 3~4 hours to myself, without even counting eating and housework.  This is quite depressing.

or is it?  let's see if I can come up with a solution.

My solution:

sleep at 11:30, wake up at 6:30 instead, and exercise for an hour. 
screw music and pictures, do them during the weekend
study Mongolian while skyping.  My girlfriend is Mongolian anyways. (wait, did I say girlfriend?)
I usually have two hours of prep period during school (it's not much.  Korean schools have 0~7 periods, sometimes 8).  Practice writing at school.

So this pretty much solves everything, on paper at least.  Now, I'll have some fried chicken and beer to celebrate the successful creation and solution of the self-improvement list.  All this will start tomorrow, after my nap.  It always starts tomorrow.

I haven't taken many pictures lately.  But for some reason, the motivation is coming back.  May be it's because of the Steve Job's commencement speech at Stanford (more on this later).  I dunno, but anyways, I want to take pictures again. 

The problem is, I'm really sick of my current camera & lens, but I really can't afford a new camera right now.  The Nikon D7000 + couple lenses will easily be about $3,500.  I mean, I do have the money, but I don't think I should spend it.  What should I do?