Rate of return regulation and the Le Chatelier principle

This paper examines whether rate-of return regulation alters the input quantities firms use to produce their selected output level when the corresponding input prices change, in a manner similar to the Le Chatelier principle. More specifically, would the change in a rate regulated firm’s input quantity due to a change in its input price be less price elastic than the unregulated firm’s change in the input quantity due to a change in its input price. We follow Färe and Logan (1986), Nelson and Wohar (1983) in estimating a rate regulated cost function and capital input share system of equations. Using a 1992–2000 panel of 34 US major investor-owned electric utilities, empirical results indicate that the regulated own-input price elasticities of demand for labor and fuel are less price elastic than their corresponding unregulated own-input price elasticities of demand (a Le Chatelier principle type effect). Having a fuel clause (1) reduces the firm’s willingness to substitute from fuel to either non-fuel (capital, labor) input when the price of fuel rises, and (2) enhances the firm’s willingness to substitute from non-fuel inputs to fuel when the price of non-fuel inputs rises.