LESTER W. MILBRATH AND ROBERT C. SAHR PERCEPTIONS OF ENVIRONMENTAL QUALITY* (Received 8 November, 1974) I. INTRODUCTION For the past ten years there has been a great deal of discussion concern- ing environmental degradation. But what do we mean when we say an environment is degraded? A related concept, quality of life, also has come prominently into public discussion. Here again, what do we mean by 'quality of life'? Large public programs and, possibly, total judgments about the performance of governments are based on implicit definitions of the meaning of these terms. It is the purpose of this paper to offer a conceptual and operational definition of environmental quality which is reliable and valid, which is sensitive to life-style differences, which can be used in a number of cultures, and which can be used for comparisons across time. This aspiration is not modest and we cannot as yet claim that we are entirely successful. We do believe that our approach is promising and that the effort can be improved with helpful criticism from others. It is not intuitively obvious why measures of environmental quality are useful and hence why it might be important to develop them. We see three important kinds of uses. First, as implied above, they can be an important indicator of system performance. Nearly all public manage- ment systems aspire to a high level of environmental quality. Presumably that is an essential element for a high quality of life. Environments which insult or injure the humans who live in them necessarily detract from quality of life. Measurements of environmental quality, taken at regular intervals, provide a useful indication of how well a political system is ' performing in this regard. Perhaps more importantly, they can indicate in what respects the efforts of a system are succeeding and in what respects they are failing. Secondly, environmental quality measures can be used as a tool for S Social Indicators Research 1 (1975) 397--438. All Rights Reserved Copyright 9 1975 by D. Reidel Publishing Company, Dordrecht-Holland