Most of the world’s biggest oil producers are raising output even as budgets shrink, showing that past investments are still boosting volumes amid the worst crude-market collapse in a generation. Four of the five most valuable producers, which account for about 16 percent of global supply, increased output last year, according to company reports. The industry as a whole reduced capital spending by 24 percent and may make deeper cuts in 2016, International Energy Agency Executive Director Fatih Birol said Monday. “We are raising alarm bells,” Birol said at the annual IHS CERAWeek conference in Houston. “The historic investment cuts […]