Reproduced, with permission, from:On a priori logic, economic growth need not worsen pollution. But, empirical evidence to prove the point is not always easy to find. A recent study suggests, however, that income growth has been associated with reduced pollution over significant ranges of per capita income.*
The study is based on data collected by the Global Environmental Monitoring System (GEMS). The GEMS project - a joint venture of the World Health Organization and the United Nations Environmental Programme - has monitored air quality in urban areas throughout the developed and developing world since 1976. Concentrations of sulphur dioxide and suspended particles are measured frequently by comparable methods in several different locations in each of the participating cities.
Analysis of the data related the levels of pollutants to various characteristics of the sites and cities (whether the site was situated in the city-centre or suburbs, whether the city was situated on a coast or not, its population density, and so forth) and to the level of per capita GDP in the country in which the city was located.
The chart below - depicting the variation in sulphur dioxide pollution attributable to variation in per capita income across countries and time - is typical of the study's findings. Concentrations of SO2 have risen with income at low levels of per capita GDP, fallen with income at higher levels of per capita GDP, and eventually leveled off in the most advanced economies. The estimated turning point comes at about $5,000 (1988 US dollars). The conclusions for smoke pollution are much the same as those for SO2 pollution.
