Project Data - Mint Date And Number Of Circulating Coins

Singer - Thanks for the reply.
We had already looked at the US Mint site and data. However, it isn't quite what we're looking for.

So, for one example from the site, we know there were 1,053,478,300 cent coins minted in 1958. But obviously all of those coins are not in circulation still. We were trying to get info for each coin and the number of that coin for that year that is believed to still be in circulation for this year and as many other years that would be reasonable.

So, we need reasonable approximations for "number of coins in circulation" for cents, nickels, dimes, and quarters for each year starting at 2014 and going back to a reasonable date. We didn't see this at the US Mint site.

The Mint's annual report gave a little data, but still not to the level we are needing.

I don't know of any place you could find estimated coin circulation by year and denomination and that would be a pretty massive undertaking to even get close. I'd guess you might have to take each years mintage and give it a rate of exit from circulation that increases each year after it's production, and then add in any variables you can find to specific dates. You might find some valuable info in the roll hunting threads in these forums, especially for cents as many of us post some figures per box (links at bottom). Then you can plug in some of the variables specific to certain dates.

A few notes
CENTS
Key Dates will be nearly non-existent in circulation 1909, 1914, 1931
All copper cents (pre 1982) are hoarded. On avg I see about 15% pre-1982 cents per 2500 box
2009 cents are hoarded for various errors and varieties and lower mintage.
Many S mintmarks pre-1975 are hoarded (but they are only 5-10% of that years total mintage)

NICKELS
Key Dates 38, 39, 50
Pre-1964 Nickels are collected
1964 had massive mintage and therefore nearly no collector interest. That combination means you are very likely to have a 1964 nickel in your change.
2009 low mintage spurred heavy hoarding (on average I find 1 per box of 2000 nickels)

DIMES
Virtually no dimes pre-1965 will be found because silver.
No key dates after 1964 that would dent circulation much except 2009 which are hoarded like cents, nickels from that year.

QUARTERS
Same with dimes for pre-1965 Silver quarters
1976 bi-centennials were hoarded heavily and many have returned to circulation as the value never really went up. Their loss rate from circulation has been protected as a result.

State Quarters 1999-2008 are collected pretty heavily and would have higher than normal rate of loss from circulation
---coins minted per resident (each state done individually then averaged for the year) *how much a factor this is depends on rates residents collected any of their State Quarter specifically. Probably less likely than collecting the full set.
1999 307
2000 362
2001 517
2002 127
2003 143
2004 67
2005 181
2006 480
2007 471
2008 325

2009-2014 maybe less of an increased rate of loss than the State Quarters but a bit higher than prior to 1999


Coin Roll Hunting threads for cents and nickels. Dime and Quarters mostly post only silver finds and not much for statistics. You may have to dig just a bit to find the better posts with full box stats.
https://goccf.com/t/24785
https://goccf.com/t/38685

rdlem - Wow! Getting closer to what we are looking for. I am thinking the actual data I am looking for will not exist. So we will have to take the known minted amounts and do some kind of "rate removed from circulation" function on each coin for each date.

The information you gave will at least have some actual reasoning and logic to develop the function with, instead of a half-random guess that I was going to try to come up with.

One of the judging points of the contest is to use research and data to develop a predictive model. She will then run her model numerous times and come out with averages for what should be the expected dates on the coins received as change. She then will actually go out and make small purchase and see if the coin dates matches the predicted coin dates.

We could do the purchases first, tally the coin dates, and then make a computer model that would predict the coin dates received as change with significant reliability, but that would be counter to the whole process and point of the competition.

Thanks again for the input. I am feeling a little less worried about being able to help her get this done. We have over five months to work on this project.

ProAmerica - Yes, it is somewhat complicated - especially for a 6th grader, but she is a very sharp student.

The complicated part will be dealing with the known data to develop a reasonable "rate removed from circulation" function. If the data was known already, it would be a simple program based on probability. I am feeling very optimistic about the outcome of this project after rdlem's reply.

CreightonE

To give you some idea of what is out there in circulation the following is offered. I do roll searches of Lincoln Cents and offer the following info as to what I have found in circulation:

Wheat Cents (1909 - 1958) found 1,481
Copper Cents (1959 - 1981) Found 55,727
Copper Cents (1982) found 6,888
Canadian Cents (all years) found 587

Total cents searched 282,500

Comments: Copper Cents from 1982 only include those coins that are copper based. The U.S. mint coined both a copper and a zinc base coin. Coins were switch in maybe August or September. So the number of coins for 1982 is much smaller than is representative of coins produced.

This is only true statistics that I keep. Maybe some other forum member could provide numbers for other coins.

Help?

Appears to be an interesting assignment for a 6th grader.

I have done extensive research of Jefferson nickel circulation obsolescence .... although the data only covers the years 1938 - 1959

You can read the basis of the methodology at this thread:

http://www.coincommunity.com/forum/...PIC_ID=58454

My latest update was at 300,000 nickels searched. You can view that data at this thread:

https://goccf.com/t/163828

Best of wishes on your project.

David

I would give up on trying to find the "actual" numbers left in circulation--the dynamics of circulation, hoarding, and coin durability are far too fickle to calculate with any reasonable accuracy. Especially at a level appropriate for sixth grade statistical analysis.

What I would focus on is the concept of "half-life" and how it relates to other things--in this case, coins left in circulation. For the sake of the project, forget that rare and old coins are typically preserved better than common ones. Have your student do some research on "average coin life" in circulation to get an idea of how long a given denomination can survive the task of being used before it is too worn out and must be retired. For example, the number used to justify all of the various $1 coin programs is that a $1 coin will last 25 years in circulation compared to a paper dollar's 2 year average.

From there:

(At the risk of doing the work for you)

1. Gather mintage information for each year from the Internet (Wikipedia has comprehensive lists of most denominations)
2. Calculate each year's mintage as a percentage of the total denomination mintage (this can be done easily through Excel once your data are entered)
3. Using each coin's half-life in circulation, determine how many coins are "retired" each year (say a coin minted in 2004 has a half life of 10 years and a mintage of 1,000,000,000. In 2014, we would expect 500,000,000 to be freely circulating with 5% of the remaining population being retired each year)
4. Determine estimated total remaining population in circulation
5. Calculate probability of receiving a specific coin from circulation

And as a bonus:

6. Have your student check their data against actual numbers; e.g. estimate how many 2003 cents are left in circulation, and have them pull all 2003 cents from a $25 box of cents to check their estimate.
7. Have your student put together a collection of coins in varying conditions to show how coins deteriorate over time. Ask them to think critically about why condition and age may not always correlate.
8. Have your student extrapolate their data to estimate when the surviving population of a particular year will be equal to 1. Ask them to think critically about why their data will never show "0". (At the risk of teaching an 11-12 year old about limits )
9. Have your student research the relation between mintage, condition, and rarity in "classic" series such as Morgan and Peace dollars. Note that price and rarity correlate only weakly within these series. Challenge your student to discover why. (Answer: Many of these coins sat unused in government vaults until the 1950s while others circulated heavily. For example, an uncirculated 1885-O Morgan may be worth $30, while an 1892-O may be worth $200, despite being in the same condition and having a reasonably similar mintage.) Ask how perceived rarity might affect a coin's surviving population in the future (the 1950-D nickel is a prime example--just over 2,000,000 were made, but the public was aware of this and consequentially almost the entire population was pulled from circulation and survives to this day).

Hope that gives you some good ideas! Obviously, what is outlined above would be quite a task for a 6th grader. I would personally advise that you focus on one denomination (Cents 1959-2014 or Nickels 1938-2014 would be my recommendation) and would strongly recommend challenging your student to complete 6) above as a way to reinforce how to test hypotheses with real-life data. It may seem like a lot of money, but remember that you can always bring them back to the bank for a 100% refund!