Moody’s Investors Service agreed to a $863.79 million settlement with the Department of Justice, 21 states and Washington, DC, late last week. The settlement focused on rating activities between 2004 and 2010 involving residential MBS and collateralized debt obligations. According to the settlement, Moody’s used an internal ratings model for most tranches of certain residential MBS that was more lenient than its published guidelines, allowing for lower credit enhancement levels than what the published guidelines required. The internal model was based...