Analysis of the major drivers of the ecological footprint using the STIRPAT model and the PLS method—A case study in Henan Province, China

Taking Henan Province of China as an example, we computed and analyzed the ecological footprint (EF) in 1983–2006. The results showed that the EF in Henan Province quadrupled in the 23 years, but its ecological carrying capacity (EC) was rather low and was in a state of slow decline, indicating that Henanʹs ecological deficit (ED) had become a remarkable social problem. Therefore, the major drivers of the EFʹs change were analyzed. According to the simulations with STIRPAT model, the major drivers of Henanʹs EF were human population (P), GDP per capita (A1), quadratic term of GDP per capita (A2), percent of economy excluded in the service sector (Ta1) and percent of urban population (Tb1). However, these drivers themselves had strong collinearity, which might produce some uncertain impact to the final results. In order to avoid the impact of collinearity, the method of partial least squares (PLS) was used. The results showed that the major drivers of EF were P, A1, A2 and Tb1. Ta1 was excluded. Compared with the results by the STIRPAT model, which showed that P is the most dominant driver and the effect of the other drivers could almost be ignored, the results by PLS method were considered as more reasonable and acceptable because the impacts of the A (Affluence) and T (Technology) conditions to the regional EF were still too important to be ignored. In addition, the results acquired by both methods showed that the curvilinear relationship between economic development and ecological impact (EF) or the classical EKC hypothesis didnʹt exist in Henan Province.