7 - Marginal Utility and the Volatility of Prices

Summary

In the early neoclassical era, the smooth adjustment of agents’ marginal utilities dampened the response of market prices to supply disturbances. But when agents do not make smooth trade-offs, they will tend consume goods in specific combinations, as in the model of safety bias. A negative shock to supplies can then send prices soaring, a common feature of energy markets for example. Postwar general equilibrium theory permits agents to be safety-biased but has dismissed these volatility scenarios on the grounds that they occur only at vanishingly unlikely output levels. The no-volatility conclusion fails to hold however once the production of goods is taken into account: the seemingly unlikely output levels arise systematically. Production on the other hand spells out countervailing forces that curb the most extreme cases of price volatility. Volatility is closely related to the indeterminacy of equilibria and the chapter critiques the claims of general equilibrium theorists that these phenomena are unlikely.