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Rarity scale questions
chesterb
Posts: 961 ✭✭✭✭✭
What is more scarce? R-4+ or R-4-
Is there a guide that describes what the R values mean?
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chesterb
Posts: 961 ✭✭✭✭✭
chesterb
Posts: 961 ✭✭✭✭✭
chesterb
Posts: 961 ✭✭✭✭✭
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In order of decreasing rarity...
R4+ > R4 > R4- > R3+ > R3, etc.
https://www.novanumismatics.com/the-various-numismatic-rarity-scales/
Rarity 4+ is ~81-100 pieces according to Overton rarity scale.
BHNC #248 … 108 and counting.
I find Dave Bowers' URS scale to be much more useful and precise.
By the time availability reaches a Judd R-1it is actually common. Any coin with over 1250 is easy to find, except due to the price. Expensive coins with noticeably less than 1250 are usually easy to find. Some rarity scales have multiple increments for common coins but just calls it "scarce" or "rare".
Thanks all. So it appears for the typical US silver early type coin that the Overton scale is used?
You could also use the CoinFacts rarity scale:
https://pcgs.com/coinfacts/rarity-scale/6495
I still like the URS scale best-
Universal Rarity Scale Number of Coins
URS-1 1 known, unique
URS-2 2 known
URS-3 3 or 4 known
URS-4 5 to 8 known
URS-5 9 to 16 known
URS-6 17 to 32 known
URS-7 33 to 64 known
URS-8 65 to 125 known
URS-9 125 to 250 known
URS-10 251 to 500 known
URS-11 501 to 1,000 known
URS-12 1,001 to 2,000 known
URS-13 2,001 to 4,000 known
URS-14 4,001 to 8,000 known
URS-15 8,001 to 16,000 known
URS-16 16,001 to 32,000 known
URS-17 32,001 to 65,000 known
URS-18 65,001 to 125,000 known
URS-19 125,001 to 250,000 known
URS-20 250,001 to 500,000 known
I prefer the specificity of the URS scale as well.... It would be nice if we could agree on one scale as standard for the hobby.... Yeah, just a dream... like getting any standards in coin collecting. Cheers, RickO
That's still kind of confusing to me.
I'd love to have a Self-explanatory Rarity Scale:
For simplicity I prefer the Sheldon scale. I use it for analyzing slab pop. I have many graded world coins and banknotes with slab pops in single or just double digits.
I don't care for it for a few reasons. First, it runs in the opposite direction of well-established scales. Yes, it allows the scale to be expanded to higher numbers meaning higher populations, but nobody cares about the highest populations enough to warrant introducing that confusion. Second, while scale is touted as universal, the concepts of common and scarce are not universal. For some types, URS-12 is a rare coin worth a premium, while for others it is common as dirt. The traditional R-scale uses the R-numbers to mean specific levels of rarity, where those then map to populations. The URS number could just as easily, and perhaps more usefully, be presented as log2(population) + 1. A more useful scale would have the familiar 8 steps for every context, ranging from super-common to unique. For any given context, you'd start with the maximum population would wanted to represent (Pmax), where R-1 would be that number or more. The rest of the scale falls in place behind that, as an exponential scale with the base = exp(ln(pMax)/7). R-n would mean a population of at least base^(8-n), but no more than base^(9-n) - 1.
Keeper of the VAM Catalog • Professional Coin Imaging • Prime Number Set • World Coins in Early America • British Trade Dollars
I would also combine this with other resources, including your own observations.
I had a half dime from New Brunswick that appeared 'rare' by looking at the combined NGC/PCGS pops. But then I realized many are also certified by ICCS, and looking on eBay there are a number that are still raw.
For US coins, large cent rarity can also be deceptive if you only look at certified pops. Many are raw, or won't straight grade if they were/have been submitted. Fortunately these have been pretty extensively studied for many decades, so we have a pretty good feel for absolute rarity for most varieties.
Not sure exactly how you are using it but the manner in which you imply doesn't seem to be meaningful. Have no idea of banknotes but for world coins, the low populations are predominantly due to collector preference (they don't like slabs) or there is little economic benefit to having it graded. Most coins (US or world) are a lot more common (even in higher grades) than indicated by the TPG data.