The highest retail gas prices in years are raising concerns about one of the longest-running U.S. economic expansions on record. Drivers across the U.S. have paid as much as $2.96 a gallon on average this year, the most since 2014. Prices have climbed to $3.63 in California and $3.39 in Washington, states where prices tend to be higher because of factors such as higher taxes, environmental regulations requiring cleaner fuel and a lack of pipelines that transport oil west. With wages in the U.S. climbing , Americans have so far been able to weather the higher prices. But analysts say that if average gas prices hit $3.50 or even $4 a gallon as global oil prices rise, that could dent growth by eating into disposable income and spending. U.S. airlines have already increased ticket prices, and over time higher energy and manufacturing costs can eat into company profits, slowing […]