When Does Regulation Distort Costs? Lessons from Fuel Procurement in US Electricity Generation: Comment
重新检验了Cicala（2015）关于美国电力重组对燃料采购成本影响的研究，发现其估计结果对异常值不稳健，修正后影响减半且不显著，异常值主要来自一家公司在重组讨论前已重新谈判煤炭合同的电厂。
We revisit one of the results in Cicala (2015) and show that the previously estimated large and significant effects of US electricity restructuring on fuel procurement are not robust to the presence of outliers. Using methodologies from the robust statistics literature, we estimate the effect to be less than one-half of the previous estimate and not statistically different from zero. The robust methodology also identifies as outliers the plants owned by a single company whose coal contracts were renegotiated before discussions about restructuring even started.