Pollution Abatement Costs and Foreign Direct Investment Inflows to U.S. States: A Nonparametric Reassessment
用非参数方法重新检验Keller和Levinson（2002）关于污染治理成本影响美国各州外商直接投资流入的结论，发现部分参数结果不稳健，且影响程度比之前认为的更小且因州而异。
Keller and Levinson (2002) utilize state-level panel data on inflows of foreign direct investment along with an innovative measure of relative pollution abatement costs to assess the impact of environmental stringency on capital flows. Using standard parametric panel data models, the authors find moderate evidence that capital flows are sensitive to abatement costs. Using recently developed nonparametric methods, we assess the robustness of this conclusion. The nonparametric approach reveals that (a) some of the parametric results are not robust, and (b) the impact of relative abatement costs is heterogeneous across states and generally of smaller magnitude than previously suggested. Copyright by the President and Fellows of Harvard College and the Massachusetts Institute of Technology.