attrition rates for older coins

GOLDSAINT

Who out there might have some statistical data on the attrition rate for coins through the centuries?

Does anyone have a formula?

So here is an example: if a coin was minted in 1600, how many of the original mintage can we assume survived, and what potential grades should we break these down into?

TwoKopeiki

It's impossible to calculate attrition for old coins. We cannot identify how many survivors we have, plus different series would have been subjected to different treatments (areas of circulation, frequency based on denomination, different rates of degradation of different alloys, etc).

secondrepublic

It's impossible to determine the exact rate. I've a seen a Polish catalog use a very loose rule of thumb for early 20th century coins that probably 20% survived on average. But that's one country, one time period, with a very specific history.

Take a coin like the Lincoln cent that was never formally withdrawn from circulation by the government. All the "wheaties" from 1909-1958 are pretty much out of circulation since the 1960s and 70s. The wheaties that circulated longer (the early dates) should have lower survival rates, unless they were saved for some occasion like the first year coins in 1909 or maybe the steel cents which are distinctive.

That's just one coin, one specific fact pattern. For world coins with different political and economic histories, the stories are much different. I'll give one example from my own area of knowledge, pre-war Poland. The 1932 5 zlotych "Nike" was withdrawn from circulation / bank stocks in early 1933 and melted down and a new, devalued 5 zlotych with less silver was introduced. Catalogs estimate that maybe 25 examples exist; I estimate the survival to be around 100, maybe even 150 or 200 based on the fairly decent number that I have seen at auction over the years.

Given that the coin was minted in 1932 and barely had time to circulate, you would expect the survivors to be largely in very nice condition. And you'd be wrong to think that. Virtually no specimens exist in UNC condition, and you see a lot in VF with a fair amount of wear. Why is that the case? No one knows. In that case, we have a mystery about both the surviving numbers -- why 100 or 150 and not 1000 -- and the condition of the survivors.

coinpictures

I'm thinking it is a completely impossible task.

Just on the lightside alone there are MOUNTAINS of labor and research just trying to ascertain that very information on Morgan dollars, given (1) hoards of bank bags, versus (2) huge melt-offs in the 1960s and in 1980 at the height of the silver boom. And that's with the U.S. mint having fairly good records and the coins being of comparatively recent origin.

Similarly, the task of trying to figure out survival rates of U.S. half cents and large cents given the melts of copper during the U.S. civil war.

Now you want to go back to 1600, when in many cases original mintage figures aren't even known.

It's not like there's a formula that you can plug the original year and mintage into, and voila!

There are just too many variables and too much unknown information.

And that's just for raw survival data, let alone attempting to make a stab at what grades the surviving coins are in...

Yikes!

worldcoinguy

Interesting question, but I would think there are simply too many variables to give a concise answer. You would have to approach the topic with a very specific geographic area in mind, and a specific period of time. A few unknown factors that come to mind include:
- economic trends (might impact the rate of circulation of lower denomination coins?)
- political cycles and rulers/governments
- policies regarding monetary control/reform (periodic devaluation of coinage, melting coinage from previous years to support minting activity, etc)
- population influx/decrease/migration over time
- outside influence/rule/occupation by another country (was it a colony or territory of a larger country, etc)
- conflicts/wars

cladking

I think a good rule of thumb is a 3% attrition for very low value coins while they are circulating
and going down to about .5% for high value coins and gold. (This assumes full circulation) Once
they go out of circulation then the rate drops to .5% to 1% depending on value and conditions
of the society which holds them. Wars dramartically increase attrition. When coins are withdrawn
to be destroyed there will be relatively little destruction of specie and much higher destruction of
high value base metal coins. Low value base metal coins are more likely to be kept as souvenirs.
If coins are to be demonetized there will be more destruction.

If you figure 1% for low value coins then you'll probably not miss by too much. Collector coins will
have a much lower loss because they are protected much more.

Much of the attrition for many coins is highly episodic. Mardi Gras doubloons were common as
cajun rice kernals in New Orleans but many were lost in the flood. The Spanish 100P silver coins
were melted in the mid-'80's. The Pittman act wiped out more than a hundred million silver dol-
lars. Sometimes this attrition ois less obvious. Millions of Indonesian aluminum coins were dis-
tributed to kids in this country in the early '60's and these were often lost or discarded.

Cereal manufacturers put millions of coins in with the cereal and many of these are now gone.
Many aluminum coins are such low value that they are just "consumed" in circulation. When the
recall finally comes there's nothing left to recall.

DeutscherGeist

I still have my Polish and Brazilian coins that I got from the cereal box in the 80's. I was a kid then and thought these might be worth lots of money later. Well, I have them still. They are in their original holders. Are they worth anything? I think they might have come out from Super Suger Crisp.

GOLDSAINT

Thanks for all your replies, as I expected a very tough job. Like most of you the world books I have measure about 16 inches tall when stacked up. I have no idea how KM keeps up with world prices. The Friedberg Gold book I have was published in 2003 so must have been put together in 2002, so pretty outdated.

What is everyone using for a gold book now?

For those of you that have not gone to look at coinpictures website, you need to do that, what a great site.

shirohniichan

I'd think some coins have higher surviving populations because of shipwreck discoveries. This not only applies to Spanish galleons, but also to US coins from the California gold fields.

Coins commonly used as bullion (i.e. trade coins) were commonly melted, also. Many silver coins sent to Hong Kong in the late 19th century were sent to Bombay and Calcutta for melting and reminting into Brotosh trade dollars.