Recent research by economists Moritz Schularick and Alan M. Taylor have confirmed the theory that economic booms are fueled by an excessive growth of credit. They have written a paper titled “Credit Booms Gone Bust: Monetary Policy, Leverage Cycles and Financial Crises, 1870–2008″ (http://www.nber.org/papers/w15512), published by the National Bureau of Economic Research.
A major cause of the Great Depression was a credit boom, as analyzed by Barry Eichengreen and Kris Mitchener in their paper, “The Great Depression as a credit boom gone wrong” (BIS Working Paper No. 137, http://www.bis.org/publ/work137.pdf). Eichengreen and Mitchener cite Henry George’s Progress and Poverty as providing an early theory of booms and busts based on land speculation. They also credit the Austrian school of economic thought, which in the works of Friedrich Hayek and Ludwig von Mises, had developed a theory of the business cycle in which credit booms play a central role. Henry George’s theory of the business cycle is complementary to the Austrian theory, as George identified the rise in land values as the key role in causing depressions.
An expansion of money and credit reduces interest rates and induces a greater production and purchase of long-duration capital goods and land. The most important investment and speculation affected is real estate. Much of investment consists of buildings and the durable goods that go into buildings as well as the infrastructure that services real estate. Much of the gains from an economic expansion go to higher land rent and land value, so speculators jump in to profit from leveraged speculation. This creates an unsustainable rise in land value that makes real estate too expensive for actual uses, so as interest rates and real estate costs rise, investment slows down and then declines. The subsequent fall in land values and investment reduces total output, generates unemployment, and then crashes the financial system.
I note without comment that for a short time as a young man F. A. Hayek was very much taken with Georgist ideas …