For an industry prized for its discretion, private equity’s problems have become uncomfortably public. Despite a pickup in dealmaking in the latter half of the year, the industry is sitting on a backlog of at least 31,000 companies valued at 3.7 trillion, according to the most recent data from Bain & Company. That’s higher than last year’s 29,000-company record backlog valued at 3.6 trillion. Private equity firms typically make money for their investors, such as pension funds and endowments, by buying c ...