4Peter H. Lindert(2004). Growing Public: Social Spending and Economic Growth Since the Einghteen Century. Cambridge University Press, London, UK.
5Amartya Sen discusses the difference between a stock and flow in "The Concept of Wealth, " In The Wealth of Nations in the Twentieth Century: The Policies and Institutional Determinants of Economic Development, ed. Ramon Myers (Stanford: Hoover Institution Press, 1996).
