6Summers L.Reflections on the new "Secular Stagnation hy- pothesis" [A].In C.Teulings and R. Baldwin (eds). Secular stagnation: Facts, causes and cures[C].London: CEPR press, 2014,ip.27-38.
7Faylor J. and Williams J. Simple and Robust Rules for Mon- etary Policy[R]. NEBR Working Pa- per,2010,No.15908.