Peter Mandelson, former U.K. business secretary, pauses during a debate on the fringes of the party's annual conference in Brighton, U.K., on Monday, Sept. 28, 2015. U.K. opposition leader Jeremy Corbyn recruited Nobel Prize-winning economist Joseph Stiglitz and wealth and inequality expert Thomas Piketty to advise his party as he seeks to regain credibility for policies attacked by many academics as potentially disastrous. Photographer: Chris Ratcliffe/Bloomberg via Getty Images