Exploring the relationship between wellbeing, environmental stress and income

A recent paper by Michigan State University's Thomas Dietz et al. in Applied Geography explores the relationship between people's wellbeing, income and environmental stress of 58 different countries. They found that wellbeing for a given amount of environmental stress will be high at both and high and low levels of affluence, and lower at intermediate levels of affluence. This pattern is known as a Kuznets curve.    

ABSTRACT
The environmental Kuznets curve (EKC) posits an inverted “U” shaped relationship between the affluence of a nation and the stress it places on the biophysical environment, with increases in affluence from low to moderate levels producing increased environmental stress but further increases eventually leading to a tipping point after which further affluence reduces environmental stress. We hypothesized that the same pattern might obtain for the relationship between affluence and the efficiency with which a nation produces human well-being compared to the stress it places on the environment. The environmental intensity of human well-being (EIWB) was represented as the ratio of a nation’s per capita ecological footprint to its average life expectancy at birth. Using panel data on 58 nations, we find that, on average, the relationship between gross domestic product per capita and EIWB is a U shape, the inverse of the Kuznets curve.