Environment and productivities in developed and developing countries: the case of carbon dioxide and sulfur dioxide.

We propose a productivity index for undesirable outputs such as carbon dioxide (CO(2)) and sulfur dioxide (SO(2)) emissions and measure it using data from 51 developed and developing countries over the period 1971-2000. About half of the countries exhibit the productivity growth. The changes in the productivity index are linked with their respective per capita income using a semi-parametric model. Our results show technological catch up of low-income countries. However, overall productivities both of SO(2) and CO(2) show somewhat different results.