Minimum Lagrange multiplier unit root test with two structural breaks

The endogenous two-break unit root test of Lumsdaine and Papell is derived assuming no structural breaks under the null. Thus, rejection of the null does not necessarily imply rejection of a unit root per se, but may imply rejection of a unit root without break. Similarly, the alternative does not necessarily imply trend stationarity with breaks, but may indicate a unit root with breaks. In this paper, we propose an endogenous two-break Lagrange multiplier unit root test that allows for breaks under both the null and alternative hypotheses. As a result, rejection of the null unambiguously implies trend stationarity

Are C02 Emission Levels Converging Among Industrial Countries?

ABSTRACT Time paths of carbon dioxide emissions in twenty-one industrial countries are examined from 1960-1997 to test for stochastic and conditional convergence. Both panel unit root tests and cross-section regressions are performed. Overall, we find significant evidence that C02 emissions have converged

Minimum Lagrange Multiplier Unit Root Test with Two Structural Breaks

The endogenous two-break unit root test of Lumsdaine and Papell is derived assuming no structural breaks under the null. Thus, rejection of the null does not necessarily imply rejection of a unit root per se, but may imply rejection of a unit root without break. Similarly, the alternative does not necessarily imply trend stationarity with breaks, but may indicate a unit root with breaks. In this paper, we propose an endogenous two-break Lagrange multiplier unit root test that allows for breaks under both the null and alternative hypotheses. As a result, rejection of the null unambiguously implies trend stationarity. © 2003 President and Fellows of Harvard College and the Massachusetts Institute of Technology.