(Reuters) - European Central Bank President Mario Draghi has moved closer to launching sovereign debt purchases and data this week will show just how dangerously low inflation has fallen in the $13 trillion euro zone economy. A sickly Europe has held back global economic growth for years, and now it is contributing significantly to powerful forces already dragging down inflation across the globe. A spectacular drop in crude oil prices over the past month will be the center of discussion when ministers from the world's top oil exporters meets in Vienna on Friday.