Statistical Analysis Of Key And Semi-Key Buffalo Nickels

For background information, I posted a similar thread on Lincoln Cents:

https://goccf.com/t/88992#735292

Now for the Buffalo nickels. I thought I would treat these as a single group, and also compare my findings with the current price (as found on numismedia.com for G4.)

From the LWC study: key date z-values were found to be -2.2 and less; semi-keys between -2.2 and -1.5.

To get a z-value, I determine the relative standard deviation from the mean (log mintage) values. The results for the "top 10" Buffalo nickels are as follows:

1926-S -2.10
1931-S -1.91
1913-S T2 -1.91
1924-S -1.75
1915-S -1.71
1921-S -1.68
1913-S T1 -1.42
1927-S -0.99
1914-S -0.98
1914-D -0.87

Interestingly, the lowest mintage coin 1926-S is not that low relatively speaking. The top 6 would make semi-key definitions based on the LWC series.

I then compared the price (G4 based on numismedia.com) with these z-values. The graph below shows the log (price) on the y-axis and z-value on the x-axis.

These results are interesting. First of all, the general trend is there (higher prices/lower mintage), but the spread of the data is a lot more than I saw with the other series (LWC, IHC, Mercury dimes, and Walkers).

Comments? Thanks for reading...