Discussion - Member to Member Sales - Research Center
Discussion - Member to Member Sales - Research Center
To me the relevant items are:
P: Print volume
Y: Year of Issue
C: Country (1 to 3)
S: Subject (0.5 to 2)
The last two are entirely subjective. If I consider a country common, like the USA, Canada, Australia the value will be 1 (or less). If the country is less common like Vanuatu, Tonga, Fiji, Bolivia, Bahrain etc , I can assign a value of 3 to this coeficient
Subject - same thing. If it is a subject I collect - the value will be 2. If the subject or artistic value is not very desirable, I can go with 0.5.
So this is my formula, provided the year is only between 1830 and 2020.
Price(USD) = (20,000 x (58.7143-0.02857 x Y) x C x S) / P
You can play with it and have some fun. I have not tested it for the Penny Black or other rare stamps.
Login to Like
this post
What a creative person you are. I could never put something like this together. I rely on my gut, which works . . . most of the time anyway.
Login to Like
this post
I always thought that dealers used one of these to set the price of covers:
Just give it a good spin.
Jan
5 Members
like this post.
Login to Like.
What do the constants stand for in your formula?
Funny that you mention the Penny Black, because this would be an example of how reality defies objective formulas. Strictly speaking it is not a very rare stamp, but special circumstances (it being the first stamp) make it very desirable. So the demand is huge, which drives up the price beyond objective reasoning.
On the other end of the spectrum, I had a very rare San Marino stamp, less than 10,000 printed. Its catalogue value was similar to the Penny Black but it proved virtually impossible to sell it even at 25% of c.v. In the end I traded it with someone for a bunch of stamps I wanted. Everybody happy 
Login to Like
this post
"Funny that you mention the Penny Black, because this would be an example of how reality defies objective formulas. Strictly speaking it is not a very rare stamp, but special circumstances (it being the first stamp) make it very desirable. So the demand is huge, which drives up the price beyond objective reasoning."
Good catch Jansimon. I was expecting this one to come up! Yes, I have no variables for demand in my formula.
The two funny numbers in the formula are the "a" and "b" in a linear equation (y=a*x+b) which assumes that stamps printed in 1830 are 5 times more likely to have been destroyed over the years as those printed in 2020. The digits after the decimal point are not very important, but I left them to have the thing look scientific
Yes, one can do better, but this one can give me a good feeling every time I buy something like your San Marino stamps.
Login to Like
this post
This penny black went today for CA$215 and no I did not buy this one.
G.B. #1 VF Used 1840 1d Black Plate 1A position H-A
1 Member
likes this post.
Login to Like.
05:17:13am
Auctions
Hey Jules.
Just checking your formula and believe you should change "S" to "The Square Root of S-Squared".
I think that would make it look even more scientific.
Happy to help out, David.
2 Members
like this post.
Login to Like.
07:50:30pm
" .... The Square Root of S-Squared ...."
Really ?
Login to Like
this post
07:57:56pm
Auctions
It's a math joke, Charlie! One of many I use that never gets a laugh. Hence my picture...
1 Member
likes this post.
Login to Like.
Very interesting, cougar!
I have a wide background in parametric (and nonparametric) statistical methods. Would be interested in seeing your scatter plots of the data.
I suspect the relationships are not linear. Here's a good (isolated) example:
There were only about 6000 copies issued of DWI Scott number 20 (the 10c bicolor, perf 13) that were not overprinted. Yet, this stamp is often vastly underpriced in the marketplace, relative to it's scarcity.
-Paul
Login to Like
this post
04:34:48pm
One of many I use that never gets a laugh.
That was my grimly ironic chuckles'
Login to Like
this post
Approvals
I thought I would come up with a value calculation formula just for fun.
To me the relevant items are:
P: Print volume
Y: Year of Issue
C: Country (1 to 3)
S: Subject (0.5 to 2)
The last two are entirely subjective. If I consider a country common, like the USA, Canada, Australia the value will be 1 (or less). If the country is less common like Vanuatu, Tonga, Fiji, Bolivia, Bahrain etc , I can assign a value of 3 to this coeficient
Subject - same thing. If it is a subject I collect - the value will be 2. If the subject or artistic value is not very desirable, I can go with 0.5.
So this is my formula, provided the year is only between 1830 and 2020.
Price(USD) = (20,000 x (58.7143-0.02857 x Y) x C x S) / P
You can play with it and have some fun. I have not tested it for the Penny Black or other rare stamps.
Login to Like
this post
re: Catalog Value Calculation Formula
What a creative person you are. I could never put something like this together. I rely on my gut, which works . . . most of the time anyway.
Login to Like
this post
10:53:54pm
re: Catalog Value Calculation Formula
I always thought that dealers used one of these to set the price of covers:
Just give it a good spin.
Jan
5 Members
like this post.
Login to Like.
Auctions - Approvals
re: Catalog Value Calculation Formula
What do the constants stand for in your formula?
Funny that you mention the Penny Black, because this would be an example of how reality defies objective formulas. Strictly speaking it is not a very rare stamp, but special circumstances (it being the first stamp) make it very desirable. So the demand is huge, which drives up the price beyond objective reasoning.
On the other end of the spectrum, I had a very rare San Marino stamp, less than 10,000 printed. Its catalogue value was similar to the Penny Black but it proved virtually impossible to sell it even at 25% of c.v. In the end I traded it with someone for a bunch of stamps I wanted. Everybody happy
Login to Like
this post
Approvals
re: Catalog Value Calculation Formula
"Funny that you mention the Penny Black, because this would be an example of how reality defies objective formulas. Strictly speaking it is not a very rare stamp, but special circumstances (it being the first stamp) make it very desirable. So the demand is huge, which drives up the price beyond objective reasoning."
Good catch Jansimon. I was expecting this one to come up! Yes, I have no variables for demand in my formula.
The two funny numbers in the formula are the "a" and "b" in a linear equation (y=a*x+b) which assumes that stamps printed in 1830 are 5 times more likely to have been destroyed over the years as those printed in 2020. The digits after the decimal point are not very important, but I left them to have the thing look scientific
Yes, one can do better, but this one can give me a good feeling every time I buy something like your San Marino stamps.
Login to Like
this post
re: Catalog Value Calculation Formula
This penny black went today for CA$215 and no I did not buy this one.
G.B. #1 VF Used 1840 1d Black Plate 1A position H-A
1 Member
likes this post.
Login to Like.
05:17:13am
Auctions
re: Catalog Value Calculation Formula
Hey Jules.
Just checking your formula and believe you should change "S" to "The Square Root of S-Squared".
I think that would make it look even more scientific.
Happy to help out, David.
2 Members
like this post.
Login to Like.
Silence in the face of adversity is the father of complicity and collusion, the first cousins of conspiracy..
04 Mar 2021
07:50:30pm
re: Catalog Value Calculation Formula
" .... The Square Root of S-Squared ...."
Really ?
Login to Like
this post
07:57:56pm
Auctions
re: Catalog Value Calculation Formula
It's a math joke, Charlie! One of many I use that never gets a laugh. Hence my picture...
1 Member
likes this post.
Login to Like.
08:50:54am
re: Catalog Value Calculation Formula
Very interesting, cougar!
I have a wide background in parametric (and nonparametric) statistical methods. Would be interested in seeing your scatter plots of the data.
I suspect the relationships are not linear. Here's a good (isolated) example:
There were only about 6000 copies issued of DWI Scott number 20 (the 10c bicolor, perf 13) that were not overprinted. Yet, this stamp is often vastly underpriced in the marketplace, relative to it's scarcity.
-Paul
Login to Like
this post
Silence in the face of adversity is the father of complicity and collusion, the first cousins of conspiracy..
05 Mar 2021
04:34:48pm
re: Catalog Value Calculation Formula
One of many I use that never gets a laugh.
That was my grimly ironic chuckles'
Login to Like
this post