Statistical Analysis of Coins Lost in Circulation by Ephraim Goldin, Journal
of Business & Economic Statistics, 1985, vol. 3, issue 1, pages 36-42

http://links.jstor.org/sici?sici=0735-0015(198501)3%3A1%3C36%3ASAOCLI%3E2.0.CO%3B2-0

Such factors as illicit exportation, melting and counterfeiting (to name but 
a few of a long
list of likely significant and uncontrolled variables) have plagued all 
previous econometrical
attempts at analyses of coinage [lost] in circulation ... few analysts have 
even acknowledged
such problems ... e.g., this article gives figures on the current levels of 
counterfeit Euros
[and, of course, the stated number of 164,000 counterfeit coins having been 
removed from
circulation in 2006 by central banks grossly understates the magnitude of 
the problem, and
does not even acknowledge the millions of "undetectable" bogus Euros known 
to have
been injected by state-sponsored counterfeiters, viz North Korean) :

http://europa.eu/rapid/pressReleasesAction.do?reference=MEMO/07/19&format=PDF&aged=1&language=EN&guiLanguage=en


----- Original Message ----- 
From: "geoff carver" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, October 19, 2007 4:43 AM
Subject: age of coins in circulation


i heard a lecture recently, in which someone mentioned a small experiment, 
where he tallied the dates of the coins in the pockets of his acquaintances, 
and i was wondering if anyone has seen reference to anything more 
systematic? i know philip barker makes reference to the problems of trying 
to date the contents of someone's pockets based on the coins he tried to use 
to make a phone call, but i was wondering if there might have been a more 
systematic study done somewhere, sometime, and not necessarily by 
archaeologists (banks or mints, to guage the age of coins in circulation?)