Quote:
Originally Posted by The_Cave_Troll  MIdas, I looked at the Heritage numbers that you posted earlier and did a little statistical analysis....
Anyway, For NGC 65 coins the average price was $78.78 with a standard deviation of $5.08.
For PCGS 65's the avearge was $97.11 with a standard deviation of $6.88.
That means that the PCGS 65 coins sell for an average of 23.28% more, but they have a standard deviation that is 35.5% more! |
Thank you, Thank You, THANK YOU. This is exactly the sort of analysis that is needed.
One of the concerns I have about this particular set of numbers... it is for a Lincoln cent, which has the designation
BN, RB, or RD in addition to the numerical grade. I don't see any correction for that, since Midas didn't include that detail in his stack of numbers.
That factor alone adds much to the standard deviation, since BN, RB, or RD sell for dramatically different prices.
Another MAJOR factor to watch for when using Heritage's history to look for price trends... since ANACS places problem coins in holders*, beware when you see an ANACS price half of the NGC price. It's not because ANACS sucks... it's because that ANACS coin was a problem coin. That fact is hidden when looking at the big stack of numbers.
That illustrates why NGC was wise to place problem coins in NCS holders... it distances the NGC name, brand perception, and value perception away from the lower value problem coins.
* plainly and clearly labeled as problem coins 
