多谢！ 2# liuningzheng

ANALYSIS
Questioning the empirical basis of the environmental Kuznets
curve for CO2: New evidence from a panel stationarity test
robust to multiple breaks and cross-dependence
Diego Romero-Ávila⁎
Pablo de Olavide University, Department of Economics, Carretera de Utrera, Km. 1, 41013 Seville, Spain
A R T I C L E I N F O A B S T R A C T
Article history:
Received 23 October 2006
Received in revised form
7 February 2007
Accepted 11 March 2007
Available online 2 May 2007
This paper investigates the time series properties of per capita CO2 emissions and per capita
GDP levels for a sample of 86 countries over the period 1960–2000. For that purpose, we
employ a state-of-the-art panel stationarity test which incorporates multiple shifts in level
and slope, thereby controlling for cross-sectional dependence through bootstrap methods.
Our analysis renders clear-cut evidence that per capita GDP levels are nonstationary for the
world as a whole while per capita CO2 is found to be regime-wise trend stationary. The
analysis of country-groups shows that for Africa and Asia, per capita CO2 is best described as
nonstationary, while per capita GDP appears stationary around a broken trend. In addition,
we find evidence of regime-wise trend stationarity in both variables for the country-groups
consisting of America, Europe and Oceania. The results of our analysis carry important
implications for the statistical modelling of the Environmental Kuznets curve for CO2, since
the differing order of integration in both variables for the world as a whole and for Africa and
Asia calls into question the validity of panel cointegration techniques which assume that
both variables are nonstationary and cointegrated with one another. Cointegration
techniques would not be appropriate either for the case of America, Europe and Oceania
which are characterised by per capita GDP and CO2 emissions being stationary around a
broken trend. Similar conclusions are reached when we analyse country-groups based on
levels of development. Failure to properly characterise the time series properties of the data
by not controlling for an unknown number of structural breaks and for cross-sectional
dependence could be responsible for the fragility and lack of robustness surrounding the
estimation of environmental Kuznets curves.
© 2007 Elsevier B.V. All rights reserved.