Bad Arguments: Correlation & Causality

On December 14th, 1957, in the Journal of the American Medical Association; Vol. 165, Num. (15), an article was featured about the "Correlation between Marriage & Hair Loss in Men".

The study, was conducted all across the United States. It captured every state, and nearly every occupation for men at that time. The findings of the study sent shocks to every man across the country.

"When compared to men who were not married, married men were 76% more likely to experience hair loss."

The study gained so much attention, that both the Harvard School of Medicine & the John Hopkins School of Medicine later re-ran an identical study, only to conclude identical results!

Men across the country now looked at the alter as the beginning of a receding hairline. The implicit conclusion that was drawn was the following:

"Since there is a correlation between marriage & hair loss, therefore, it must be the case that marriage causes hair loss."

On the face of it, it seems logical enough (perhaps to a non-logician).

Nearly a decade later, the academic community of statisticians featured a mock journal to poke fun at the medical community.

The article talked about the correlation between clapping your hands every second, and children in Africa dying. As the study concluded, there was a perfect correlation of (1)! Which meant, every time you clapped your hands each second, there was actually one child in Africa dying!

The statistician who wrote the article then concluded; "therefore, if we wish to stop the death of children in Africa, we should all stop clapping our hands!"

To translate the academic humor, what the statistician was eluding to was, that "correlation" does NOT imply "causality".

Phrased differently, it was not BECAUSE anyone was clapping their hands, that a child in Africa was dying. The only reason "clapping your hands every second" & "a child in Africa dying every second" had a correlation of (1), had nothing to do with each other, other than the simple fact that they shared a common duration of TIME; "one second".

Similarly, as was later discovered, "marriage" didn't CAUSE "hair loss". DHT & Cortisol (byproducts of age & oxidative stress) caused hair loss. Since married men, tended to be OLDER & in more demanding jobs & family lives, they were more subjected to the factors necessary for hair loss; than say, unmarried men. Therefore, although marriage might have had a correlation with hair loss, as the American Medical Association later pointed out; marriage didn't in fact CAUSE hair loss.

So what motivated me to write this article?

For some reason, Yahoo news featured an article from an Attorney in Florida, who is clearly not yet married; but clearly wants to be. In her attempt to do so, she made a desperate & sad attempt to try and convince her male readers that:

"Marriage causes wealth!"

Therefore, "If you get married, you will be more wealthy!"

Her argument?

Premise: Unmarried couples who have two rents to pay, higher taxes to pay, and twice the expenses to pay for living separately, accumulate less wealth over the course of ten years, when compared to married couples who have only one rent to pay, a married filing jointly standard deduction as opposed to two single deductions, and pay living expenses jointly.

Conclusion: Therefore, being married is what causes one to accumulate more wealth! So if you want to accumulate more wealth, get married!

After reading it, the first thoughts that came to mind were:

- How did she pass the Logical Reasoning portion of her LSATs?
- How did she pass Law School?
- How did she pass her BAR Exam?
- I guess the BAR in Florida must be pretty low.

But then I started to take a step back and think, this chick already knows what she's talking about! She's just skewing her evidence, to support her point. So the best way to attack her faulty argument, is to simply highlight the aspects of her evidence, that she's stating (since it's the truth, and she doesn't want to lie), but she's simply failing to highlight; since it wouldn't really do wonders in supporting her argument.

1. Saving taxes: If your argument is that MFJ is the BEST filing status for both people working, then I have to disagree. Head of Household is the best. You get better rates for ONE INCOME, and a higher standard deduction for ONE INCOME. The MFJ standard deduction, is simple TWICE the single standard deduction. and if both people are working, it makes no difference if they either file as MFJ or both file as single!

2. Cost sharing: In economics, it's called the "economies of scale". There are things that can be used by more than one person, but whose expense must only be incurred once! (such as rent & heat, and cleaning supplies or other household items). If two people are living together, and split the costs of these items together, than the difference means savings for them! But they NEED NOT BE MARRIED to do so!

3. Advanced Negation Test: Let's put "marriage" to the test. If her argument is that "marriage" CAUSES "wealth", then let's consider Couple M (married), who lives separately, pays two rents, two heating bills, two laundry bills, and two of everything. Let's consider Couple U (unmarried), who live together, and although are also both working, split costs since they live together. According to this Florida Attorney's argument, at the end of each month, and definitely by the end of a 10 year period, Couple M's wealth should be significantly higher than that of Couple U's.

Okay, let's not beat a dead horse. I think it's obvious that this chick is probably getting old & desperately wants to convince a guy to marry her ASAP!

But it's worth pointing out that it's not "Marriage" that CAUSES wealth, nor is it "living together"! It's "Cost-Sharing" that causes wealth.
Bad Arguments: Correlation & Causality
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