Convergence Analysis of the Sanitation Index for 158 Countries

Since 1990, 2.1 billion people in the world gained access to improved sanitation. However, 2.4 billion people still do not use a basic toilet. We examine whether the country differences in the sanitation index existing in 1990 has been reduced and if so, how fast. We deploy the convergence methodology to answer these questions for 158 countries. Results of our analysis indicate that the sanitation index for 158 countries are converging toward a catch-up process as well as a reduction of dispersion. However, significant variations are discovered in the speed and timing of the convergence processes for the subgroups of countries by income and regions. Implications of our finding will be discussed