With declining textbooks revenues, Houghton Mifflin Harcourt’s $3.1 billion in debt was downgraded last week to a lowly Caa 3 rating by Moody’s, which said the publisher’s finances are “unsustainable without a significant rebound in earnings” and judged “a debt restructuring in the near term is increasingly likely.” The ratings service says privately-held HMH’s sales fell […]