The oft cited argument that environmental regulation stymies productivity is based on biased measures of economic activity, argues a new book. The authors of "Has Environmental Protection Really Reduced Productivity Growth?" by the World Resources Institute (WRI) of Washington DC say that traditional measures only take account of the costs of reducing pollution -- but not the cost of pollution damages averted. Electric power is one of the industries re-analysed in this new book, which disputes that environmental regulation starting in the 1970s hampered economic productivity. The report is one of four new reports issued by the WRI in late 1996.