Is There A Half-Life For Coins In Circulation?

Well I was off on Lincoln Cents, according to the article around 76% are tossed/lost every year. Or maybe they are all in glass bottles saved for eternity.

Maybe more like 66%?

But remember, we are part of that loss rate every time we pull a wheatie out, or save our change in a jar. It doesn't necessarily mean the coins are lost.

Ooops typo. (I'm sticking with the typo, NOT that I can't subtract 34 from 100)

Several factors influence circulation of particular coins or denominations.
Intrinsic devaluation quickly drives out coins with higher intrinsic value (Gresham's Law). This can be seen with CNC replacement of 90% silver coinage in the U.S. and with nickel and plated steel replacement of 80% silver coinage in Canada.
Convenience can drive out coins that are less convenient. Small cent replacement of large cents and nickel five cent replacement of silver five cent coins are examples. The large cents were awkward compared to the small cents, and the tiny fish scales were too easily lost.
Design changes can make earlier designs disappear prematurely. Advent of the Jefferson nickel in 1938 hastened the exit of the Buffalo nickel from circulation. Conversely, popularity of the Kennedy half dollar in 1964 caused their withdrawal from circulation, leaving later date Franklin half dollars still circulating until replacement of the 90% silver coinage made all of them disappear.
Awkward denominations disappear because of the disdain for the denomination. As an example, Twenty Cent coins proved far less popular in commerce than twenty-five cent coins, leading to premature withdrawal of Twenty Cent coins.
Functionally useless denominations disappear because they are not worth circulating. The one cent piece in Canada became that way long before withdrawal of the denomination. They are not functionally circulating in the US either.

A better study would be the lifespan of popular longer-term denominations that have not experienced recent design or metallic changes. In the U.S., that would include Jefferson nickels and CNC Roosevelt dimes.

Just my Two Cents' worth. Oh wait, they don't circulate either.

I understand your point on this, and it rings well with common sense when there are abrupt changes (like from, silver to CuNi), but multiple studies have shown that in normal circumstances, the "loss rate" of low denomination coins is highest.



@Silver, What do you teach?

Yep, me too (General Chemistry and Introductory Organic/Biochem). Double the work right now since I am doing video-conference style lectures, but I also need to post a lot of extra materials for students who don't have the bandwidth to dial in (it's an inner city school). Spent the last day before lock-down photographing steps in some labs so we can do them in "virtual" fashion.
Still haven't figured out how I'll do exams.

Personally, I cannot walk past a penny without picking it up. I guess I am helping the economy by returning it to the mix.

I admit, however, that I do not recycle really, really pitifully damaged pennies. I usually hoard them until I have a dozen or so and then trash them.