How did Scott conclude its toilet tissue lasted 28% longer?

Dear Cecil: Scott tissue, in its advertisements, used to claim that each roll of its paper was 1,000 sheets, 500 sheets longer than any other brand. Yet it claimed that the additional 500 sheets made it last 28 percent longer. How did the Scott people arrive at the 28 percent figure? If there are 100 percent more sheets in one of its roll, shouldn’t it last 100 percent longer, not 28 percent? Anonymous, Phoenix

Cecil replies:

You’d think so, all right. However, we are dealing here not with the crisp elegance of mathematics, but the fetid swamp of human nature. We ought to point out, first of all, that in a Scott roll you’re getting 1,000 one-ply sheets, while in some competing brands you get 500 two-ply sheets. The total volume of paper involved is not vastly different. What does vary is how people use the stuff. The penetrating eye of science has found that there are all kinds of toilet-paper techniques in this world. There are wadders; there are folders; there are people who would probably go to jail if it was known what they did with their toilet paper. Some people use, say, five sheets per pass (note ingenious euphemism) no matter what brand they encounter, while others use enough to make an acceptable handful, which means they’d use more of a thinner tissue. The fact that you get more linear feet of TP in a Scott roll does tend to make it last longer, but exactly how much longer depends on the individual user. Scott’s dedicated research team learned that on the average a Scott roll would last 30-35 percent longer than other rolls, a figure they trimmed down to 28 percent for safety’s sake.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.