Impacts of Migration on Urban Environmental Pollutant Emissions in China: A Comparative Perspective

Abstract

In recent years, researchers have devoted considerable attention to identifying the causes of urban environmental pollution. To determine whether migrant populations significantly affect urban environments, we examined the relationship between urban environmental pollutant emissions and migrant populations at the prefectural level using data obtained for 90 Chinese cities evidencing net in-migration. By dividing the permanent populations of these cities into natives and migrants in relation to the population structure, we constructed an improved Stochastic Impacts by Regression on Population, Affluence and Technology model (STIRPAT) that included not only environmental pollutant emission variables but also variables on the cities’ attributes. We subsequently conducted detailed analyses of the results of the models to assess the impacts of natives and migrants on environmental pollutant emissions. The main findings of our study were as follows: 1) Migrant populations have significant impacts on environmental emissions both in terms of their size and concentration. Specifically, migrant populations have negative impacts on Air Quality Index (AQI) as well as PM2.5 emissions and positive impacts on emissions of NO2 and CO2. 2) The impacts of migrant populations on urban environmental pollutant emissions were 8 to 30 times weaker than that of local populations. 3) Urban environmental pollutant emissions in different cities differ significantly according to variations in the industrial structures, public transportation facilities, and population densities.