Average profits of a price taker are increasing in the variability of the output price (Oi, 1961). We show that, for the same reason, average profits of the price taker are increasing in the variability of the price of inputs. We proceed to establish that the same holds for a firm with a...

To the surprise of many, price deviations between markets characterized by imperfect competition have often been little affected by lower transport costs. In a Cournot model we show that if firms' decisions to segment markets are endogenous, then lower transport costs are, in many cases,...

In this paper two simple tests to distinguish between unit root processes and stationary nonlinear processes are proposed. New limit distribution results are provided, together with two F type test statistics for the joint unit root and linearity hypothesis against a specific nonlinear...

This paper considers testing the unit root hypothesis against a smooth transition autoregressive model as the alternative. The model specification makes it possible to discriminate between nonstationary random walk and stationary nonlinear processes. Some new limit results are presented,...