In the investigation, they checked if economic growth affects the environment differently as countries develop. They examined data from 11 emerging countries between 1977 to 2013. By using special statistical methods, they discovered that the more the economy grows, the ecological footprint also grows but there is a turning point where it starts getting smaller again. This suggests a U-shaped relationship between economic growth and its impact on the environment. Moreover, they found that economic growth and environmental impact influence each other in both directions. This means that as economies grow, they can harm the environment, but also, environmental degradation can slow down economic growth.