[1] Cullen Murphy,Are We Rome?The Fall of an Empire and the Fate of America(New York:Mariner Books,2007).

[2] Paul Kennedy,The Rise and Fall of the Great Powers:Economic Change and Military Conflict Among the Great Powers from1500to2000(New York:Random House,1987).

[3] Of course,there were many more causes of this complex phenomenon.See Ramsay MacMullen,Corruption and the Decline of Rome(New Haven:Yale University Press,1988).

[4] See Nicholas Kristof,"We're not No.1!We're not No.1!"New York Times,April3,2014.

[5] "The jobs machine,"The Economist,April13,2013.

[6] Klaus Schwab and Xavier Sala-i-Martin,The Global Competitiveness Report2013-14(Davos:World Economic Forum,2013).Niall Ferguson,"How America lost its way,"Wall Street Journal,June7,2013.

[7] Technically Recoverable Shale Oil and Shale Gas Resources:An Assessment of137Shale Formations in41Countries Outside the United States(Washington,DC:US Energy Information Agency,2013),p.3.

[8] 2014Global R&D Funding Forecast(Columbus:Batelle Memorial Institute,2014).

[9] US Patent Statistics Chart,Calendar Years1963-2013(Washington,DC:The United States Patent and Trademark Office).

[10] For a more optimistic view of American savings,see Richard N.Cooper,"Global imbalances:Globalization,demography,and sustainability,"Journal of Economic Perspectives22,Summer2008,p.95.

[11] Niall Ferguson,"An empire at risk,"Newsweek,December7,2009,p.28;and"A Greek crisis is coming to America,"Financial Times,February11,2010.See also,Francis Warnock,"How dangerous is US government debt?The risk of a sudden spike in US interest rates,"Council on Foreign Relations Report,June2010;available at: