Convergence of carbon intensity: a test on developed and developing countries.

: Carbon intensity refers to the carbon emission of per unit output generated by a country or a region. It shows the economic system's close connection with carbon emission and its direct or indirect influence on environment. The carbon intensity curves of many countries visually show significant features of convergence. In order to strictly testify this phenomenon, this thesis chronologically defines convergence of carbon intensity and testifies it with endogenous growth model as theoretical basis. To realize the empirical test on convergence of carbon intensity, the author selects 24 countries as test samples and divides them into 3 groups, on which σ convergence test and cointegration test are conducted. Test result shows that convergence of carbon intensity exists in countries with high or medium high income, while countries with medium or low income shows insignificant convergence tendency in carbon intensity. Besides, σ convergence test demonstrates the time and degree ranking of convergence of carbon intensity of the 3 groups, which provides a concrete referential standard for countries to analyze and control changes in carbon intensity.