Of course copper % are dropping…but copper isn't drying up

[Shifty51]

We all know there is a lot of discussion on the forum about a drop in the % of copper being found in circulation. That drop in % is just a natural part of the game and the drop will continue year after year regardless of how many cents sorting removes from the game. I ran some numbers to show why the % will continue to decline even if all sorters stopped today.

To make things easier for this example we will assume 2 things…
1) All cents minted in 1982 were clad (both clad and copper pennies were produced in 1982)
2) Every penny ever minted is still in circulation in some form

1981
At the end of 1981, in this example the last year any copper pennies were minted, a total of 167,175,779,275 Lincoln cents had been minted since 1909. As we all know the likelihood of finding a copper cent in a box or roll of pennies at the end of 1981 was 100%...Man wouldn’t that be nice!!!

1982
Let’s fast forward to the end of 1982. A year in which, for the sake of this example, all pennies were clad. If that were the case, 16,725,504,368 clad pennies were introduced into circulation in 1982 bringing the total number of pennies in circulation up to 183,901,283,643. 167,175,779,275 of that total being copper. So by the end of 1982 your likelihood of finding a copper penny in a box or roll would be
167,175,779,275 / 183,901,283,643 = 90.9%.

1983
By the end of 1983 14,219,554,428 clad cents were added to circulation bringing the total number of pennies in circulation up to 198,120,838,071 of which the same 167,175,779,275 copper cents were in circulation. By the end of 1983 the likelihood of finding a copper penny in a box or roll would be
167,175,779,275 / 198,120,838,071 = 84.3%

1984
# of clad cents added to circulation in 1984 = 13,720,317,906
Total of cents in circulation at the end of 1984 = 211,841,155,977
Chances of finding copper cent = 167,175,779,275 / 211,841,155,977 = 78.9%

So within 3 years of the govt. no longer producing copper cents the percentage of copper coins in circulation had dropped just over 21%. This all due to more clad being introduced to the total number of coins and the number of copper remaining the same.
Now we all know that every cent ever minted is not still in circulation but we can see in this example how the % of coppers has diminished and will continue to do so each year. Coin sorters do have an impact on the number of coins available, but I feel that simply the introduction of more copper cents has more of an impact on the drops in percentages we are seeing.

Note: If this example were carried out to the end of 2014
# of clad cents added to circulation in 2014 = 8,146,400,000
Total of cents in circulation at the end of 2014 = 485,786,740,960
Chances of finding copper cent = 167,175,779,275 / 485,786,740,960 = 34.4%

People are seeing roughly 13% - 20% in boxes these days. I feel the difference between the 34.4% and the % of what sorters are seeing today has far more to do with the natural loss of copper coins in circulation over the last 106 years than it does the actions of us coin sorters/hoarders. I would argue that relatively speaking, even with the action of coin sorters both large and small the total amount of copper out there is the basically the same, we just have to go through a lot more clad to find it.

Please fell free to disagree.

[coppernickel]

Thank you for doing the math.

I have wondered what these numbers were, but not enough to figure it out.

[Cu Penny Hoarder]

I've removed one ton of Cu pennies from circulation over the past 5 years. I stopped last year.

I've been averaging the Cu pennies I receive in my change. It's only about 7-10% these days and it only gets worse as time goes by.

I'm keeping what I have, but I'm done now. It's just not worth the effort anymore.

[Dr. Cadmium]

Logical and nice to see explained. However, while your second assumption makes the math much easier, it's an important factor.

Consider adding the following statistics, which I've come across:

A) The average lifespan of coins in circulation is 30 years.

B) 1-2% of coins are lost "underfoot" (from metal detecting discussions). I'm sure the mint has estimates for the % of coins that drop out of circulation every year. The reasons are many - loss, fires, piggy banks, hoarding.

You can use for these figures, especially A, to come up with a "rate of copper decay". When you do, you'll find that initial 34.4% chance of a penny being copper is closer to the actual results people here are reporting. Interestingly, as time goes on B is less important, because fewer of the coins dropping from circulation are copper.

Coin circulation certainly is a chaotic system. It's impossible to predict entirely, but the general pattern is less copper in circulation.

[Dr. Cadmium]

Also, another point is that zinc pennies are less durable than copper ones, so they fall victim to corrosion and drop out of circulation faster than copper ones. Not accounting for copper hoarding, the average circulation time for a copper cent is higher than that of a zinc one.

I sense the genesis of a mathematics thesis here.

[coppernickel]

I have printed and read this post. I think the data from both comments are amazing.

I've been sorting small time for several years, this is extremely helpful.

Thank you for the insight.

[hobo finds]

One thing to remember is a lot of times these coin hoards are returned to the wild by family that cant understand why so many pennies were kept... So at times a lot of copper can get put back into the system. I still bend over to pick up a cent on the ground even the zinc ones!

[Dr. Cadmium]

One thing to remember is a lot of times these coin hoards are returned to the wild by family that cant understand why so many pennies were kept... So at times a lot of copper can get put back into the system.

Yes, copper gets put back into circulation every day, but the net loss of coins each year is what you're concerned with. This takes into account coins being put back into circulation. I'm sure the mint has this figure. When coins are put back into circulation, the chances of them being copper are much lower than the chances of them being clad.

But that's another good point which clarifies that circulating coinage is a chaotic system. We can't account for all of the variables.

I pick up those pennies, too.

[fansubs_ca]

Also, another point is that zinc pennies are less durable than copper ones, so they fall victim to corrosion and drop out of circulation faster than copper ones.

Up here, this year I've actually encountered 2 "rusted" quarters! (They lose their coating
in a few spots then nature takes it's course on the steel core...) These plated coins will
not have a long life.

[AGgressive Metal]

Great OP, the "theoretical" 34% and the real world 13-20% seem to match up pretty logically when one accounts for attrition and hoarding.

Most people outisde the small world of coin processing don't realize how many coins are culled from circulation by processors for being non-machine sortable due to bends, rim dings, etc. You don't see them because they don't last long after becoming non-machine sortable, since virtually all coin processing in this country is automated/mechanized. Every coin you get at the bank or store has probably been through multiple machines and would have been "captured" out of circulation if there were any major defects.

[Madwest]

...Coin sorters do have an impact on the number of coins available, but I feel that simply the introduction of more copper cents has more of an impact on the drops in percentages we are seeing...

...I feel the difference between the 34.4% and the % of what sorters are seeing today has far more to do with the natural loss of copper coins in circulation over the last 106 years than it does the actions of us coin sorters/hoarders...

I agree. Even though intuitively it is hard to accept.

Intuitively, it would seem that Pincher Processing, Antares Metals, and Portland Mint together have likely put a dent in the population of pre-zinc cents.

Pincher Processing claims to have culled well over 100 tons and suggests that Antares Metals was processing 5x that volume.
http://www.goldismoney2.com/threads/the ... llc.28059/

Say that collectively that accounts for 500,000,000 cents. That still amounts to less than 0.25% impact on pct in circulation.

[jrf30]

My averages were 17.7% in 2012, 17.7% in 2013, 15.0% in 2014 and 13.8% in 2015. All the new Shield cents are diluting the boxes. Even the memorials are lower, as shields enter the picture more and more. When I get down to 10%, I'll probably quit.

That's with a few thousand boxes done over the 4 years.

[everything]

I think it's really hard to know, I've started tracking my boxes which currently fall in between 27-29% a little more carefully because they all have a little bit different personality that is really quite intriguing, and so I'm collecting boxes again, the % has fallen a couple points in the midwest, but when recession is looming or coming, or happening it seems percentages might go up a little bit.

I always wonder about hobbyists melting these things, it's only a penny, who would care, it's not worth anything, would certainly change the collecting hobby of the penny some day if copper ever went really high and the penny was discontinued.

[68Camaro]

With copper prices dropping and the melt ban still in place, It wouldn't surprise me if the percentages for the moment are dropping mostly only as a result of the dilution due to the large numbers of zincolns still being produced. The few of us that are hoarding them aren't yet making a dent in the total supply. If the melt ban was lifted and copper prices remained high enough to justify recycling, you would see the copper cent essentially disappear within a year or two.

[JadeDragon]

I've read that many pennies never make it past the first person in circulation. They go into coin jars or just are thrown away or lost. 1-2% lost underfoot is way too low for pennies. No one cares about pennies anymore, and a lot of people hate them. In Canada we dropped the penny and there was no outcry, no problems, and hardly much of a discussion about it. Collecting copper pennies is fun and profitable someday but all the sorters in the world will never make a dent.

However, in Canada the Alloy Recovery Program has wiped out most of the none steel dimes amd quarters. It has really reduced the Ni nickels too. Even US foins are hard to find in rolls in Canada now because the processers are pulling them all.

[mtalbot_ca]

If the mint is adding to the pile of pennies it is for the purpose of:
a) replacing pennies that have been pulled from circulation (hoarded, lost or mutilated)
b) increase the number of pennies due to the increase economic activity (ie more people = more transactions)

I'll see if I have the patience to do the math....

Cheers,

[Recyclersteve]

Thanks Shifty51 for the time you took to put your numbers in the original post, but I think a minor adjustment needs to be put in for the (guessing 5% or so) pennies which are too ugly to save (corroded, bent, etc.). I'll defer to anyone else who has better details on the numbers of non-savable copper pennies.

Also, I fully realize that some save ALL copper regardless of looks and others are more picky- perhaps because they feel if they sell to another collector they will get more money by having decent looking coppers.

[wolvesdad]

I didn't double check numbers, but: Did he include Wheat cents in the copper numbers in the original post?
2/3 of all wheat cents are 'collected' and the rest are either lost, destroyed, or show up rarely when old collections or penny jars are 'freed'.

I don't have my books with me, so... How many Wheats were minted? If we only allow for 15% of them in his numbers, does it make a significant difference?

[coppernickel]

I was working on some plumbing recently. The house was built in the 1970's nice copper pipes and zinc coated ductwork. See where this is going? Zinc corrodes copper when water is applied.
We've all seen those badly corroded zinc cents and know what is going on.

When was it identified that zinc corroded copper?

Did Uncle Sam intentionally make self destructive cents? Coins that would destruct the copper coins around them?

I put the question here because the zinc percentages may also be dropping faster than had been calculated.