The Economist implicates historians for bad statistics

This piece by the normally sane Economist was nominated to me via Twitter for a place in the Junk Charts hall of fame (This HOF was also a suggestion, it doesn't exist yet). While the chart is indeed quite shocking, the quantitative reasoning behind this piece, ironically titled "Quantifying history", is what deserves ignomity. So, I am posting it on Numbers Rule Your World instead.

The entire chart can be summarized in one sentence: human population has exploded in the 20th century. Any other commentary can be interpreted as a different way of stating this fact.

I said I wouldn't comment on the graph but I can't resist: the "21st century" is represented, with proper seriousness as befits a footnote, by the decade 2000-2010. You could be let off on probation in ordinary situations but when the chart presents the data (economic output and years lived) as proportions of the total sum, then the failure to either project to 2100 or to omit the 21st century is an offense that shocks the conscience.

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The accompanying text posits a "democratic view" that "one person's life is just as much a part of mankind's story as another's."

In statistical terms, this is stamping out diversity, and treating every individual as the average. As I pointed out in Chapter 1, ignoring variability is a horrible thing. Lots of individuals have disporportionately large influence on the course of history. To name a few that comes to mind, George Washington, Nobel, Newton, Einstein, Shakespeare, Beethoven, Lenin, Hitler, Mao, etc. etc. cannot be replaced by any randomly selected person. Today, in the US, we have a special day in celebration of selected few individuals who have changed the course of history.

History is the stories of outliers, and certainly not the story of the average. So, the entire concept behind the chart is rotten.

I also reckon that while the population has exploded in the 20th century, what has also exploded is the number of poor people. Again, one must pay attention to the distribution of people, not just the average person.

Finally, what is "economic output (1990 $)"? This metric is a recent human invention, and it measures specific conditions that are deemed important to measure by the current consensus opinion of economists and politicians. I think at least some explanation is on order before using this metric to compare people across centuries.

Comments

[SB]

2000 to 2010 is 11 years, not a decade. Contrary to popular belief, the 21st century begins with 2001.

[Gary]

One point: the chart emphasizes not only population growth but also the dramatic extension of life expectancies across much of the world. Its unit of measurement is "years lived" not "persons lived."

The gap between years lived and economic output does imply a tremendous increase in (average) living standards since the 20th century. I don't know how they measure economic output, however - considering that most human production never got anywhere near a market during wide swaths of the periods in question, part of this effect may be simply moving from subsistence to market economy. So you could take a Yoruban subsistence farmer's family from 1975 and move it to a Lagos slum in 1995 and count "increased" economic production.

[Patmmccann]

Glad to see my nomination was successful! It seems even Gary above missed that years lived is a product of life expectancy and population and his conclusion about the extension of life expectancy is not supported by the chart. This is another reason the chart is so horrible; people think "there must be some content here, what is it" and they stumble on an erroneous conclusion as Gary did (the likely true but not displayed idea that the rate of growth of life expectancy over time is outpaced by the rate of growth in output) or perhaps that the 21st century will experience massive declines in something. If one notices the footnote and projects the last bars up to adjust at some personally determined growth function, they have to simultaneously adjust the other bars down so it all sums to 100%; I like your choice of word for this: unconscionable.