An Empirical Test of Environmental Kuznets Curve for Water Pollution

The Environmental Kuznets Curve (EKC) on water pollution was investigated with both semiparametric and parametric models using watershed level data for the state of Louisiana, USA. The parametric model indicated the turning points within the range $10241–$12993, $6636–$13877, and $6467–$12758 for nitrogen (N), phosphorus (P), and dissolved oxygen (DO), respectively. However, only the parameters associated with N EKC were found to be significant. Model specification tests rejected parametric models in favor of semiparametric specification for P but not for N and DO. Copyright Springer 2005