  
| Author: | Etown  | | Posted: | Oct 1, 2018 15:16 | | Subject: | Re: 90-percentile as new average price ? | | Viewed: | 67 times | | Topic: | Suggestions | |
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| In Suggestions, Gaston.La.Brick writes:
| | I noticed the highest prices of items sold (or of items that are on sale), have
an out of proportion influence on the average prices.
Example: when 9 people sell (or have sold) an item at €0.10 but 1 person has
sold that item for €10.00, the average price would be €1.09
You may say this example is not realistic, but it's not that unrealistic
either. Check out item 6558. The avg used price of last 6 month sales is €0.023,
while the majority of the sales are for less as €0.02
If you look more closesly, you see a few sales at a high price, but not a lot.
(Note: someone even sold a few of these for €1.00 !)
It's my suggestion to change the calculation of avg price to use the 90-percentile
method. So only the 90 percent (lowest prices) are taken into account. That way,
the top 10-percent highest prices are not taken into account when calculating
the avg price.
To avoid weird behaviours, the rule could be in place only when there are 10
items sold/for sale.
Example would become an avg price of €0.10
Another somewhat more complex method would be the use the median. Not the mathematic
average, but the middle price: 50% of the sellers have a lower price, 50% of
the sellers have a higher price.
What do you guys think?
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I voted no because I am hesitant to support anything that would expedite the
race to the bottom. It's getting more and more difficult to find sets with
a large enough margin to make it worth while. Besides, adding something that
makes the calculations even less transparent isn't a good move for Bricklink
in my opinion.
Ron
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Message is in Reply To:  90-percentile as new average price ? - Gaston.La.Brick (1844) | I noticed the highest prices of items sold (or of items that are on sale), have an out of proportion influence on the average prices. Example: when 9 people sell (or [...]
(69 months ago, Oct 1, 2018, to Suggestions) |
8 Messages in this Thread: Msg 1 - Gaston.La.Brick (1844) 69 months ago Oct 1, 2018 to Suggestions
 Msg 2 - Teup (6616) 69 months ago Oct 1, 2018 to Suggestions
 Msg 3 - Gaston.La.Brick (1844) 69 months ago Oct 1, 2018 to Suggestions
Msg 4 - MidwestBrick (1855) 69 months ago Oct 1, 2018 to Suggestions
 Msg 5 - yorbrick (1185) 69 months ago Oct 1, 2018 to Suggestions
Msg 6 - Bricks_NW_UK (1367) 69 months ago Oct 1, 2018 to Suggestions
Msg 7 « - Etown (1740) 69 months ago Oct 1, 2018 to Suggestions
Msg 8 - jx (13) 47 months ago Aug 12, 2020 to Suggestions
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Canada, Alberta
