摘要：This article provides empirical evidence that environmental legis-lation affecting coal mining employment passed in 1977 had different ef-fects on Western Kentucky, where the coal is of higher sulfur content, compared to Eastern Kentucky, where coals are of lower sulfur content, while the 1990 amendments to the Clean Air Act had no statistically sig-nificant impact in either region. The 1977 law generated a statistically significant reduction in West Kentucky employment. In addition, it a p-pears that coal employment in Kentucky is correlated with coal mining employment in the US
