RESEARCH AND ANALYSIS Sustainability Indicators at the Firm Level Pollution and Resource Efficiency as a Necessary Condition Toward Sustainability Daniel Tyteca Cenne Enne~e-Enuironnement Uniuersite Carholique de Louuain, Belgium - KQpOdS electric utilities environmental indicators environmental metrics linear programming productive efficiency sustainability Address correspondence to: Daniel Tyteca Centre Entreprise-Environnement lnstitut d’Administration et de Gestion Universite Catholique de Louvain Place des Doyens, 1 51348 Louvain-la-Neuve (Belgium) tyteca@qant.ucl.ac.be I Summary After reviewing recent attempts t o develop sustainability indicators,this article shows how the principles of produc- tive efficiency can be used t o elaborate such indicators at the firm level.The theory of productive efficiency is some- what expanded t o incorporatefundamental issues of sus- tainable development: environment, equity, and futurtty. Efficiency, in the expanded notion of productive efficiency, is viewed as a necessary condition for sustainability.Work- ing with aggregate performance indicators, it is important not t o lose track of the relevant basic information.There- fore, instead of elaborating one unique indicator; we pro- pose t o implement several kinds of indicators, each of which stresses one particularfocus (e.g., environmental vs. social concems).The definition of sustainable development indicators is illustrated with reference t o a small data set of U.S. fossil fuel-fired electric utilities. In a sustainabiltty perspective, two important aspects are stressed, namely, the use of nonmewable resources and the inclusion of employment as a variable t o maximize rather than an in- put t o minimize.The article ends with a discussion of the significance of, and limits to, the proposed indicators. http://w&v.iag.ucl.ac.be/iwE/ I @Copyright 1999 by the Massachusetts Institute of Technology and Yale University Volume 2, Number 4 journal of Industrial Ecology 6 I