The U.S. national average price for a gallon of gasoline would need to move close to $3 before it starts having a negative economic impact, an analyst said. U.S. retail gasoline prices have been on a steady increase for the better part of the year. Motor club AAA reports a national average price for a gallon of regular unleaded at $2.40 early Thursday, an increase of 15 percent, or 32 cents per gallon higher than this date last year. Over the course of a year, that difference could eat into savings or discretionary spending. Gasoline prices are tied to crude oil prices and the health of the nation’s refinery infrastructure. Crude oil prices are up almost […]