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 (to produce bullion ... I must 
confess to having made a small fortune over the past three years buying-up a 
small truckload of the older Canadian "nickels," which are 99.9% pure nickel 
... which has greatly appreciated in value over that period) 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?)