Thomas Jobert

Estimating country-specific environmental Kuznets curves from panel data: a Bayesian shrinkage approach

Designing an efficient global climate policy turns out to be a difficult yet crucial task since there are noteworthy cross-country differences in energy and carbon intensities. In this article, the environmental Kuznets curve (EKC) hypothesis is tested for carbon dioxide (CO2) emissions, and as a modelling technique, the iterative Bayesian shrinkage procedure is employed to handle the cross-country differences. The results suggest that first the EKC hypothesis is rejected for 47 out of the 51 countries considered when the heterogeneity in countries’ energy efficiencies and cross-country differences in the CO2 emissions trajectories are accounted for; second, a classification of the results with respect to the development levels of the countries concerned reveals that the emergence of an overall inverted U-shaped curve is due to the fact that in high-income countries increase in gross domestic product (GDP) decreases emissions, while in low-income countries emissions and GDP are positively correlated.

Public debt in Turkey: evaluation and perspectives

The aim of this study is to analyse past and future sustainability of total public debt in Turkey. The analysis is based on econometric studies and simulations. The data are taken quarterly in order to take into account intra annual effects important in Turkey, given the strong volatility of the economy. The period covered is 1988 to 2002. The econometric analysis rejects the hypothesis of the sustainability of Turkish public debt in the last 15 years. The simulations show that to reach an acceptable level of debt, Turkey has to solve its problem of chronic inflation, stabilize its economy and adopt either a policy freezing public spending or a very active fiscal policy.

Formation and deformation of the environmental Kuznets curve for CO2 emissions

Following Roberts and Grimes (1997), we study the temporal instability of the environmental Kuznets curve for a panel of 51 countries over the period 1970-2008. Our results show that: (1) an inverted U-shape curve appears in the early 1980s; (2) the environmental efficiency increases over time as the coefficient of carbon dioxide (CO2) emissions per unit of primary energy consumption decreases; (3) there is a rising trend of the turning point income that goes from 10,000 USD in the early 1980s to almost 20,000 USD in 2008.