Numista rarity index

I think the Numista rarity index should be calculated like this:
people who have this coin/people on Numista who have at least one coin inserted in collection.
So results will be for example: 20% of Numista users who have at least one coin inserted in collection have this coin.
What do you think?

That won't work because as you might have seen from the monthly statistics threads, not many people who join this site actually enter any coins. And of the 28,000 members, how many are actually active?  Any system based on coins that members have in their collections is bound to be flawed.

Any system based on coins that members have in their collections is bound to be flawed."
Isn't this happening now?
So what if few people join the site?
It will really show how many people has that coin,  based on the total number of active users on this site.
Isn't this what we want?
To see the rarity?

Yes that is what we have now, which is why I question why we have it at all.

I wasn't just referring to new members, but all members that have joined the site but not entered coins.  if 70% of the people who use this site don't enter all their coins and only half of those have entered a US penny that would mean that only 15% of Numista users have a US penny entered in their collection that would make it a rare coin no?

It won't be rare because of instead of what we have it now, will change into a percent.
And I am pretty sure that a rating of under 10 means something like 80 % have this coin.
It will just be more accurate.

I still wonder why we need it at all, surely anyone with half a clue can see that a US penny with 10 billion mintage is not rare, and a coin with a mintage of only a few thousand is pretty rare.

Also what about rare years.  They all get lumped in with the same KM number  So if somebody picked up a 1901 1/2 franc from Switzerland and look at the rarity index of 10 they'd think that they had a pretty common coin since 80% of people have that coin.  But only 200,000 of them were minted that year and a lot were melted down in the war years and it's a hard coin to get hold of.

I say scrap the rarity system altogether.  As has been pointed out, some people have been quoting that rarity number on online auctions and it really doesn't mean anything outside this site.

I think it still has a use.
For example this coin has a mintage of 50 million but rarity 80.
It's rare in Romania not to mention in other countries.
https://en.numista.com/catalogue/pieces24466.html
One can say hey this is a common coin, but with the Numista rarity index can have a hint of the real rarity.

It may be scarce in Romania, but a quick search on E-bay brings up 30 current listings fort hat coin, so does it really deserve a higher rating?

If you look again you'll see there's 2 different coins of the same year.
And I meant that it can have a mintage of 50 mil. and still be rare.

Should the rarity index be changed a little because the user number keeps increasing?
For example if one has 1 coin it should be 99 instead of 97, so decrease a little the lowering of rating.

I think that the rarity index should show rarity for a year and mintmark rather than only type.

Unless that happens, no change to the way of calculating it makes a difference.

Like the mentioned rare coin earlier, the British one penny 1933  seems very common according to rarity index that doesn't take year into account...

Quote: KartWaythe British one penny 1933  seems very common according to rarity index that doesn't take year into account...

They are pretty common, I've got a few lying around that I'll sell you for a fair price  

The Numista rarity index has no numismatic value.
Totally nonsense.
The only thing it does it shows how many other members have that 1976 BRD Pfenning, which you also have ... no other value at all.

If the same number of members have a particular €0,01 coin as have a particular €2 coin then they're going to be shown as the same "rarity" despite the fact that the €2 is obviously worth more. You just have to make sure you realise what it's actually telling you - it's definitely not something you should use to give you the value of your coin.

Personally I assume that any coin I have is worthless, that way I can't be disappointed If the rarity index shows that not many other people on here have one of my coins, then it's generally because it's a coin that not many of them are interested in. Remember that you have your coins because you like them, not because of how much someone else thinks it's worth!