Goodwill impairments are never good news. They are admissions by management that investments haven’t panned out and projects have gone awry, but that doesn’t mean the market punishes companies for announcing a write-down. Most of the time investors have known that something is wrong, or at least worrisome, and priced that into the stock and owning the problem along with a clear plan forward can boost stock prices as much as a botched announcement can hurt it. “Our research finds that investors often perceive such moves to be good news—as long as they already knew or suspected that an acquisition…