I guess its not an easy answer, but what was the average life expectancy of ancient coins? I'm guessing that its different from Rome and major cities from provinces on the farther side of the empire and it probably varies greatly from period to period as well as denomination; maybe even popularity associated with the coin.
It is hard to answer. I guess I can guess based upon some hoards I have purchased. In the hoards, it seems to be fairly common for coins about 30-40 years to show up with "modern" coins. In that respect I would imagine they are similar to our coins today. Also like today, whenever you had a debasement of coinage, (like 1965 taking silver out, or 1982 cents), then the older coins disappeared faster than would otherwise be the case. There are many coins, (I am thinking of Antony denari), that circulated longer because they were already debased and were not hoarded until Roman coins fell below their silver level. Short answer, they left circulation as soon as current coins were more debased, short of that probably the same lifecycle of current coins.
I'm pretty sure that, at least before the high inflation of the third century, Roman coinage in general circulated far longer than modern coinage would. I believe it was Trajan who finally demonitized Republican denarii, which would have been over 120 years old at the time, and the fact that he did that means that some must have still been circulating. I recall Kenneth W. Harl writing that a rather sizable percentage of coinage was still Republican at that time, but I won't be able to double check his book until at least later tonight.
I would be surprised if Republican silver was still circulating after Nero's debasement and subsequent debasements. I know most Antony coins were finally hoarded, (Gresham's law), after Nero's debasement. A friend bought a hoard of silver once with "new" Nero coins, some lightly worn Claudius, worn Tiberius and Augustus coins, and a few very worn Antony galleys. I know some Sestertii circulated a long time, since even the revlue mark was very worn. When I said like modern coins, you have to remember our silver changing and causing mass hoarding. Look in your change, 1950's and earlier nickel still circulate, and this with mass coin colelcting going on. That is 60 years, which is somewhat similar to what most ancient hoards will show. I would bet modern coins would circulate far longer if not for us dang coin collectors.
If I recall, Republican coins continued to circulate until the reign of Trajan. Even then they weren't demonetized, per se, but simply withdrawn and recoined. By that point, they would have become so worn that the government would have been able to restrike them only at a loss. At least some of them were restruck as a restoration series, bearing the same designs but with the name and titles of Trajan appended. The same thing happened again under Trajan Decius, when the earlier denarii were withdrawn en masse and restruck as antoniniani (effectively doubling their face value). Bronze coins could circulate much longer. But, since their actual value was entirely dependent on the whims of the moneychangers, they could drop out of circulation much faster. Such was the case with many of the issues of Constantius II in the early fourth century. Meanwhile, at other times, bronzes circulated long past their "expiration date." This was particularly true in the Western half of the Empire, as well as in Egypt, during the third century. That's why so many sestertii and Alexandrian drachms are found worn today. Finally, under the Ostrogothic kingdom in Italy during the 6th century AD, 300 year old asses and sestertii (probably found in the ground) were recirculated with a new value of 42 nummi. Vespasian AE As, 77-78 AD. Retarrifed by Ostrogothic kingdom, 6th century AD
Thanks all! Actually it was my worn legionary denarius (as well as my countermarked bronze) that got me thinking about it more. Some things I found on the net suggested Marc Antony denarii could have circulated well over a century, as you said, because of the silver content. I didnt know that they restruct them bearing the same designs; thats pretty interesting. That could have doubled (even trippled, under Decius) the life of a coin.
The ancient world was more than Rome. Did it end with the coronation of Charlemagne in 800 or the Fall of Constantinople in 1453? China and India had their own independent experiences, as well. Chinese cash became uniform about 250 BC and with many minor exceptions could have circulated at par until almost 1900. On the one hand very little of the world outside of cites was on a metallic economy, with savings (hoarding) in the cities keeping older coins unworn for lifetimes. Debasements had direct effects, of course, but until coins became money of account with the "franc" about 1550, Gresham's Law was not the correct statement of the problem. Taxation drove coins out of circulation, as wealthy people had them melted and made into "plate" (household objects). In The Big Problem of Small Change, Sargent and Velde tell of a Spanish town in the late Middle Ages where Roman coins -- previously counterstruck with new values -- still circulated. By analogy to modern times, Eric Newman said in a COAC paper that colonial coppers (even counterfeits) continued to circulate in western Appalachia into the 1830s. If you think about it, the "life expenctancy" of ancient coins continues today ... They are here and they move from hand to hand. Sic semper.
Gresham's law didn't apply? I thought Gresham's law was bad money drove out good. This would explain removal of any good coins when bad coins are issued, for "plate", for burying in the river, whatever. Interesting you brought up Chinese cash. I know that because of uniformity, Chinese would dig up coins in 1850 that are dated from 100 BC and go out and spend them. However, I think the OP question was about how long would coins last in circulation, meaning being handled day to day. A 100 bc coin cannot be "in circulation" for 1900 years. It would simply wear away. Before the boom in coin collecting, it was common in England and Europe for 100 year old coins to be found in change at times. Gresham's law is the big changer, for as soon as silver leaves coins the older coins get hoarded. Short of Gresham's law actions, I would say ancient and modern coins would stay in circulation for 60-100 years, until they either wear out of get lost. Everyone thinks of hoards as how ancient coins are found, but a majority of them were simply lost and found individually by metal detectorists today.
No truer words! Whatever we do in ancient numismatics we need to be careful not to look for answers 'how the ancients did it'. Defining 'ancients' as whatever ended in 1453 or the time when struck coins started to be replaced by machine made a little later covers at least 2000 years of history. During that time there were thousands of issuing authorities doing things 'their way'. What we prove conclusively for one time and place means nothing when studying another. Rome insured a turnover of types by crediting each coin to the issuing emperor and progressively debasing the silver so many people pulled old good money out of circulation before it wore so much as to lose its extra value over the new coins. The Shahi kings in Afganistan/Pakistan region issued very close to the same design, weight and fineness coins for several centuries resulting in some coins circulating a long time. Later issues kept the weight but reduced the fineness continuing to circulate for another few centuries. The authorities saw this and made two changes to the coins I find interesting. They replaced coins of normal relief design with coins with line drawings boldly cut which would wear a lot longer before losing the major details of the coin design. Later, they reduced the diameter and increased the thickness of the coins making something that would wear less over the reduced surface area. The idea appears to have been to make a coin that could stay in circulation for a long time. Studying hoards requires care to separate a hoard deposited all at once (a cross section of what was circulating at once like the offering plate at a big church) or over a long time (the grandkids added to a pot started by great grandpa). Every one is different. That said, I see nothing to make me believe it has changed since that day. When I was a kid and silver coins were silver, we spent Mercury and Roosevelt dimes equally but saved back the Barbers (I took a couple seated liberties out of circulation in the late 1950's). Last week my change included a 1938 Jefferson nickel. We regularly see 1965 quarters. Coins circulate until they are lost or become special because the new stuff is substantially different in some way. The Romans changed types so often that there were few breaks in the series that would make people discriminate for or against a coin when picking one to spend. Nero's debasement made a break in the series caused a run on earlier emperors gust like we pulled out the 1964 quarters in massive numbers inn 1965 (show me a worn 1964 quarter). Antony's ships were easy to spot and avoid saving so they lasted forever in commerce and show up in Severan hoards. Denarii of Severus Alexander and Gordian III tend to be higher grade than Flavians because they were hoarded early in favor of the new antoniniani. Starting with the mid third century, things changed faster so we see fewer really worn out coins. Later, coins would be called in and replaced with new series with enough regularity that the details get harder to pin down. Rules also might change in, for example regions ruled by Licinius and those by Constantine. This is an interesting question but 'Average' is not a meaningful number.
