Monetary randomness and investment

This paper develops a neoclassical model in which the behavior of the money supply affects investment by affecting the real distribution of asset returns. Investment depends on wealthholders' demand for capital. A stochastic money growth rule influences portfolio choice by affecting the distribution of the inflation rate. The variance of inflation matters to wealthholders because of the existence of assets with returns that are not indexed to changes in the price level: money and bonds which are contracted in nominal terms. In a rational expectations environment, asset demands will thus be sensitive to the distribution of the money growth rate. Our principle conclusion is that an increase in the variance of the money growth rate lowers investment, which complements Tobin's (1965) result that an increase in the mean stimulates capital accumulation. The paper also represents a step toward incorporating an asset market into a macroeconomic model in a manner which takes account of Lucas' (1976) criticism of econometric policy evaluation. All variables in the model, including asset return distributions, are functions of technology, preferences and the money supply rule. Further, expectations are rational.