File photo of Robert Shiller, Yale professor, and chief economist and co-founder of financial firm MacroMarkets LLC., speaking during the Reuters Housing Summit in New York February 21, 2008. The 2013 Nobel prize for economics, which was awarded Oct 14, 2013, jointly to Americans Eugene F. Fama, Lars Peter Hansen and Robert J. Shiller "for their empirical analysis of asset prices". [Photo/Agencies]