Allgemeine Theorie der Beschäftigung, des Zinses und des Geldes
During the Great Depression of the 1930s, many governments undertook public works projects in order to create jobs and stimulate the economy. The economist John Maynard Keynes provided a theoretical justification for this policy in "The General Theory of Employment, Interest and Money", published in 1936. Following the global financial crisis of 2008–2009, some again proposed investing in infrastructure as a means of stimulating the economy (see the American Recovery and Reinvestment Act of 2009).