Been playing around with this idea of “touchstone values” in statistical literacy — values that would enable you to quickly sanity check a statistic handed to you.

Here’s a list of touchstone values for population. The numbers are brutally rounded. There’s redundancy and weirdness in the choices. The idea is not necessarily that you’ll remember that North America has 500 million people, but that you’ll remember that North America, Europe, and South America are all towards the middle 100 millions. And it’s not that it is stupendously important that you know the number of chickens in the world — but understanding how many more chickens there are than humans helps give you insight into our outsize impact on the planet, as well as understand issues of disease spread and resource contention. Knowing the number of people at Woodstock can help you judge claims there were 5 million people at an event. And so on. Anyway, very rough, but here it is. Lists on money, size, and risk will follow.

Touchstone figures: Population (BEWARE! BRUTALLY ROUNDED)

20 billion: Number of chickens in world
7 billion: Population of World (humans)

• over 50% are under 30 years old,
• over 50% live in CIA — China, India, or Africa

4 billion: Population of Asia (2010)
3 billion: Population of the World, 1960
1 billion: Population of China, Population of India, Population of Africa, Population of the Western Hemisphere, Population of the world in 1800,  number of cattle in world (2010)

600 million: Population of Europe
500 million: Population of North America
400 million: Population of South America
300 million: Population of United States
200 million: Americans between ages of 16-65
100 million: Number of Americans 16 or older *not* working (2011)

50 million: Population of England, South Korea; Number of deaths, worldwide, per year, 2010; Population of Roman Empire at height
40 million: Population of California
30 million: Number of people without insurance currently, who will be insured under “Obamacare”
20 million: Number of Americans who work in the food industry, Reported population of Beijing, Number of American college students (part and full time)
10 million: Number of undocumented immigrants in U.S., Number of restaurant workers in U.S.

8 million: Population of New York City
4 million: Number of Americans born per year, Number of Americans in first census (1790), Number of K-12 teachers (U.S).
3 million: Population of Chicago
2 million: Number of Americans that die per year, Number of college professors (U.S.)
1 million: Population of New Hampshire

500,000: Number of people attending Woodstock Music Festival
100,000: Population of Manchester, NH
20,000: Population of Keene, NH