News Corp. is doing great business. It's been generating more than $2 billion in cash a year, and getting good returns on its investments. Analysts say the stock should be almost $21 a share, rather than below $17, where it is. The gap is a “Murdoch discount,” attributed to wariness over the empire's unpredictable CEO. The gap existed after the MySpace and Dow Jones deals, and it's widened since the hacking scandal.