by Tyler Cowen
on April 20, 2007 at 12:21 pm
in Data Source |
Click here for a map, via Kottke.
Turkey I wouldn’t have guessed, and more from Ireland than Japan? Weird.
MattXIV, is the methodology really that bad. It seems pretty representative to me considerign that there are more than 700 data points drawn from multiple stores. what might be bias here that can significantly skew results?
-Different products are allocated different amounts of shelf space and promenance of location.
-Product picks may suffer from confirmation bias regarding where Walmart is believed to get its products
-Products are location clustered by purpose
-Walmart store layouts are somewhat standard
-Path travelled in store was defined in part by personal agenda (he was shopping for stuff he needed too)
-He didn’t inspect high price items kept locked up like video games
See here for a description of the method: http://www.benjaminedwards.net/Writings/walmart.htm
It doesn’t matter how large the N is; if it’s not representative (ie properly randomized or the complete population), you can’t draw conclusions about the population. The correct methodology would be randomized picks off an inventory list.
When I look at this discussion I am reminded of what happened many years ago when WMT loved to claim it was buying American and advertised that 90% of its merchandise was American. Of course they defined it as buying from an American firm. Tennis shoes from NIKE were counted as American even though NIKE did not manufacture any shoes in the US. Moreover, they had foreign suppliers sell to US middlemen firms that WMT could buy the good from so they could claim they bought the merchandise from an American firm.
It just makes me sick who makes the most money off of one pair of Air Force Ones. The shoes cost only $8 or so to make and sell for more than $200 for some models. These shoes have more of a profit margin than even Air Jordans!
In case you want a pair, here are the Jordan release dates.
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