Economists call it the “rockets and feathers” phenomenon. Rockets zoom higher, but feathers float lower. There’s pretty wide agreement that gasoline prices seem to rise quickly when oil spikes, but they don’t fall so quickly when crude crashes. There’s little consensus about why. The latest data point comes with the recent plunge in global crude oil prices; West Texas Intermediate has fallen from a summer peak of about $102 to just above $66 on Thursday. That’s a 35.3 percent drop. During the same period, the average price of a gallon of gasoline has fallen from $3.87 to $2.86—or just 24 percent. (Corrects percentage drop in gas prices.) That lag in the price drop at the pump has a fairly simple explanation: The gasoline you buy today was made with crude oil bought when prices were higher. So […]