The document discusses several studies on the relationship between environmental regulation and productivity/competitiveness. An early 1970s study found environmental regulations had a negative impact on productivity in industries like paper, oil, and steel. A 1998 study found that pollution abatement investment in pulp and paper mills reduced investment in productive capital. However, abatement investment also contributed to output. A 2005 study found plants with higher abatement costs were less efficient at both reducing emissions and production, but efficiency in these areas was positively correlated, possibly due to differences in management quality across plants.