SELLING CUTS IN THE LINE. Welcome, Knowledge Problem readers. There is a problem from the "Puzzles" section of the Journal of Economic Perspectives, long ago, about two economists who want to get to the head of the line at the butcher shop, and one offers to buy the ticket with the next number to be called from the holder of that ticket. Others in the shop objected. The problem: why would those whose position (and presumably waiting time) would not be affected by the swap object? One solution: the proposed deal is contrary to the established rule of trading, which is first-come, first-served.

Today's academic connections problem: what do HOT lanes, Great America, airport landing slots, and the Kennywood Thunderbolt (you do know Kennywood, Dr. Kiesling?) have in common?