In the past, when the U.S. imported most of its energy needs, declining oil prices were a bounty to households and businesses. A rule of thumb was simple: Oil-price drops boosted U.S. economic output. That’s become more complicated. As the U.S. has risen to become the world’s largest oil producer this year, a growing chunk of domestic investment, manufacturing output and employment has become tied to oil. Now, when oil prices fall, it risks hurting investment and hiring in important parts of the economy. At the same time, a decades-long transition toward more energy-efficient living has left businesses and consumers less sensitive to prices at the pump, meaning they don’t benefit as much when prices fall. Some economists still believe lower oil prices are a net economic positive, but the resurgence of the U.S. oil industry has upended the conventional wisdom held by many, including President Trump, who has […]