This interesting graphic from Esquire has been circulating on the internet for a while. It shows how some clothiers build a lot of extra inches into the actual waists of their 36" sizes.
I was curious as to why this might be, though I know I feel better about myself when I put on a pair of pants with a reported waist size much smaller than the reality of my waist. Quantcast.com let's you type in a website and see the demographics of the visitors of that website. It gives an index value for each demographic attribute that shows how different the attribute is from the average internet user. A value of more than 100 means that the website's visitors are more likely to have that attribute than the average internet user, and a value of less than 100 means the opposite. Here's what it looks like for Haggar.com.
I ran the Quantcast charts for each of the websites of the clothiers in Esquire's graphic, and I noticed that the less likely the visitors to a clothier's website are to be Caucasian, the fewer inches need to removed from the advertised waist size. I put this in a scatter plot and let Excel draw the regression line. While there aren't a lot of data points here, there's a pretty clear pattern nonetheless: whiter customers like to be lied to about the actual size of the pants they put on.
Meanwhile, I'm heading into Old Navy!