I’m usually very optimistic about new technologies, but I’m not looking forward to this: automatic toilet paper dispensers. Those damnable automatic hand towel dispensers are bad enough. They never dispense enough paper unless you stand there for 5 minutes waving your hand in front of the sensor. But at least wiping my hands on my jeans is a viable substitute for paper towels; the same cannot be said of toilet paper.
Of course, the justification for automatic dispensers is that people overuse paper. And they probably do, given that the marginal cost is zero. (Steve, looking over my shoulder, also observes that risk-averse people are understandably concerned with the risk of having too little paper in one's hand.) But why is that so? Why not charge by the sheet? Presumably because the transaction costs are too high: I don’t want to be depositing nickels in the toilet paper dispenser (and, Steve adds, it’s hard to reach your pocket if your pants are down). Maybe a credit-card swiper (Steve suggests "the sWiper®") would provide a viable alternative. I’d rather run the plastic once than sit there frantically waving my hand in the desperate hope of getting another wad of paper.
[Aside: This really has nothing to do with the L&S seminar, except for Steve being present to watch as I composed this post.]