Of all standard coins in circulation anywhere in the world, what fraction of their sides show a person's head?
Resolves to whatever I think is a reasonable estimate based on the market and comments - which will most likely be to market probability unless I think the market probability is wrong.
Close date updated to 2022-10-05 11:59 pm
Close date updated to 2022-10-10 11:59 pm
1,000
3.00My ballpark estimate is based on the following data points:
https://en.wikipedia.org/wiki/Currency_in_circulation lists the top currencies by value, and the top 3 are by far higher than the others. Value is not the best proxy for number of coins, but it's probably reasonable enough to get a ballpark.
Of those, bills (not coins) in circulation:
50B US - https://www.federalreserve.gov/paymentsystems/coin_currcircvolume.htm
~1 head per coin
Roughly guessing ~0.5 heads per coin average
18B Japan - https://www.boj.or.jp/en/announcements/education/oshiete/money/c06.htm/
Looks like very few heads, I'll just put it down as ~0 heads per coin average
Using a ballpark estimate that coins are roughly proportional to bills, we end up with (50*1+30*.5+18*0)/(50+30+18)/2 = 33% sides showing a head. Seems like a reasonable guess.
@jack I wanted to test the limits of what you think as "wrong probability". Now I see that 18% is wrong.
@Yev It seems a little lower than I'd expect, but more important is that a significant change in price suggests there's more information for the market to aggregate, and there's no rush to close this market.
Copying comments from the previous market https://manifold.markets/jack/what-is-the-probability-that-a-coin
https://en.wikipedia.org/wiki/Obverse_and_reverse
https://en.wikipedia.org/wiki/Currency_in_circulation
Euro area has a lot of coinage in circulation, and looks like many of them do not depict heads.
(From Yev) Here is some data on number of various european coins (and bills) in circulation: https://www.ecb.europa.eu/stats/policy_and_exchange_rates/banknotes+coins/circulation/html/index.en.html