# Category: statistics

• ## Why gender at birth is not a coin toss

I love analogies. As analogies go, many things are well approximated by the “toss of a coin”. Gender at birth is not. And it’s not for two reasons, only one of which you can probably guess. The sex ratio at birth is not 1 boy to 1 girl. As of 2017, according to World Bank…

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• ## More statistical fun from XKCD

XKCD is always good, but the statistical references are often quite insightful!

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• ## The virtual irrelevancy of population size to required sample size

Statistics and sampling are fundamental to almost all of our understanding of the world. The world is too big to measure directly. Measuring representative samples is a way to understand the entire picture. Popular and academic literature are both full of examples of poor sample selection resulting in flawed conclusions about the population. Some of…

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• ## XKCD and statisticians

I was looking for an XKCD comic to insert into a presentation on insurance regulations. Yes, I do that. I came across a comic I hadn’t seen before and that also illustrates a fundamentally important point. Enjoy.

• ## Birdy statistics

I’m not sure about this fascinating article on birds evolving to avoid cars in the US. The story is that fewer cliff swallows are being killed on the roads AND those birds killed have longer than average wings. The argument here is that longer wings make for less agility, making the birds more likely to…

• ## US Life Expectancy and the dangers of superficial analysis

Life Expectancy is going up. In general. But what really matters isn’t the general but the specifics. I know it’s hard to work through maths and actual calculations, but it doesn’t help if you run your analysis off slogans. US Life Expectancy is going up. But not as much “at retirement” as it is up…

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• ## More on gender and analytical problems

Here is another interesting story with a gender angle. A study shows that stockholders in companies with women in the Board achieved better returns than those without. The obvious and likely correct point is that women add something valuable to the Board and is the company performs better. Diversity is a good thing in general,…

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• ## Time and age and cohorts

More women than men get home loans in South Africa up to the age of 39 or so. This is fascinating in itself and needs further analysis. Unfortunately, the analysis in the linked story misses a key point. 30 year old women and 50 year old women differ in that there is a 20 year…

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