摘要：Relatively few models exist that allow for regime-dependent spatial price equilibria. This paper focuses on temporary export restrictions during international commodity price peaks. Theory suggests that export restrictions have price insulating effects and lead to multiple spatial equilibria between domestic and world market prices. Our analysis is unique in that it tests for linear versus non-linear cointegration within a smooth transition cointegration model. Applying this model to the wheat export quota in Ukraine shows that the domestic wheat price was stabilised approximately 30% below the international wheat price during the two recent price spikes. From a global point of view, the domestic wheat price in Ukraine would have increased to the same degree if no country had engaged in price insulating behaviour worldwide from 2006 to 2008.
