Further evidence regarding nonlinear trend reversion of real GDP and the CPI

This paper examines whether the CPI and real GDP for the US exhibit nonlinear reversion to trend as recently concluded by Beechey and Österholm [Beechey, M. and Österholm, P., 2008. Revisiting the uncertain unit root in GDP and CPI: testing for nonlinear trend reversion. Economics Letters 100, 221-223]. The wild bootstrap is used to correct for non-normality and heteroscedasticity in a nonlinear unit root test. The use of ‘wild bootstrapped’ critical values affects test conclusions in some cases. Results also are sensitive to the sample period examined.