The Effects of Money Supply and Interest Rates on Stock Prices, Evidence from Two Behavioral Experiments

Abstract

What is the impact of interest rate and monetary policy on the stock market? Some studies find a positive impact of expansive monetary policy on stock prices others prove the opposite. This paper examines the effects of monetary expansion and interest rate changes on investment behavior on the stock market by illustrating two behavioral experiments with students. In our experiments the increase of money supply and the decrease of interest rates had a direct positive impact on share prices. These findings support the hypothesis that extreme expansive monetary policy with low, zero or negative interest rates encourage financial bubbles on the stock market. To avoid a crash the exit from such a policy must be slow. As happened in 1929, crashes can damage the financial system and the real economy. Central banks must take this into account in their monetary policy.