415 
    
    Там же, 112–113.
                416 
    
    Там же.
                417 
    
    Carter et al., "Labor Force," in Work and Welfare, vol. 2 of Historical Statistics of the United States: Millennial Edition, 17–23.
                418 
    
    Там же, 20.
                419 
    
    "Age Shall Not Wither Them," Economist, April 7, 2011.
                420 
    
    "Researchers Find Risk-Taking Behavior Rises Until Age 50," University of Oregon, Media Relations, November 10, 2011, .
                421 
    
    Самые значительные из них – Robert J. Gordon, Christina D. Romer, Robert E. Gallman, Paul David, Stanley L. Engerman, and John Kendrick.
                422 
    
    Richard Sutch, ed., "National Income and Product," in Economic Structure and Performance, vol. 3 of Historical Statistics of the United States: Millennial Edition, ed. Susan B. Carter et al. (New York: Cambridge University Press, 2006).