I was reading an old post and someone said that the rarity scale used by Sheldon had to do with condition census. My understanding of the scale is that it has to do with survivability probability based on known examples. For instance R-2 would mean that a Large Cent was uncommon, and that it is estimated that less than 5,000 and more than 1,250 coins of that particular variety exist or have survived based on known examples. Some varieties are very common, but very few, if any, are uncirculated; while, others are rare, but more uncirculated examples are known to exist. So, if it was based on condition census, then the rarer variety would be less rare because there are more higher grade coins available for that example at least that is how I would interpret what has been said. Maybe I am misunderstanding what was being said. Does anyone know for sure if the Sheldon Rarity Table is based on Condition Census, and if so what does that mean exactly? Or is it based on survivability probability? Thanks.
It's just the number of estimated survivors. It would be tough to present rarity in regards to condition. For example, you could have an R-2 where there are two MS67s and every other surviving example is VF. It would be tough to present that as one rarity number. There is just the rarity for the date or variety and then condition rarity for the date or variety is best presented as a chart (number estimated per grade).
The rarity scale and the condition census are two totally different things. The rarity scale is based on the number of surviving specimens known or estimated to exist in ANY condition. The Condition Census is a listing of the top ten (or more for some rarer varieties) finest known specimens of each variety. In some cases where there are many MS coins known there is no actual CC because there is no way to rank the many MS coins. In other cases the CC1 or finest known can be very low grade in the case of very rare varieties, or is some case a mid grade coin for a variety that may not be the rare, but which just doesn't come nice. For example the 1803 S-262 which is maybe an R-3+ or 4- coin (around 200 estimated to exist) has the CC1 coin as only a VF-35. (My F-12 is maybe 15 to 18th finest known. You have a 262 better than VG-8 it is something to be proud of. Most 262's are G-5 or less.)
