needed for environmentally conscious manufacturing (Japan External Trade Organization, 1993).
Germany has pursued a different tactic, requiring manufacturers to "take back" their products when they are discarded by the customer. Manufacturers are encouraged to recover useful material and energy and properly dispose of what is left. These initiatives make manufacturers responsible for the products they bring to market. The concept is often referred to as "product stewardship." Because regulations like these impact companies that compete globally, environmental concerns have become strategic. Companies have begun assessing the total environmental impacts of their products over the course of the product's full life cycle (Horkeby, this volume; Johnson, this volume; Marstander, this volume). They are also refining their financial analysis of products to identify in-house environmental costs, which previously were lumped into overhead (Ditz et al., 1995; Macve, this volume; Todd, 1994; Todd, 1997).
There are also other nonregulatory forces that are part of today's industrial green game. These include the emergency of voluntary international environmental standards (ISO 14000), citizen involvement, and environmental justice issues. These forces more fully explain the incentives corporations may have for evolving toward more socially oriented goals, such as environmental protection, as Allenby (this volume) speculates. Companies today can be found anywhere on the learning curve shown in Figure 2. Companies that value environmental quality—whether by force of regulation, because they see an economic opportunity in preventing pollution, or because they recognize the strategic importance of environmental factors or want to be "responsible" companies—are among those that are assessing the value of taking action beyond basic compliance that will lead to less regulation, decreased liability, and better integration of environmental concerns with business practices.
Most environmental impacts result when materials accumulate in the biosphere. The materials may be naturally occurring and extracted from the earth, or they may be man-made. The management of materials is therefore critical to the industrial green game. One way to manage materials, which aims to avoid such accumulations, is to close the materials loop of production and consumption systems. Another is a no-growth approach based on an impractical premise of not extracting or creating the materials in the first place.4
The idea of closing the materials loop is not new. It derives from the observation that in natural systems, waste is a misnomer. Materials that are not used by a particular organism generally are used by others to grow and survive. This self-sustaining characteristic has evolved over time (Ayres, 1994), and, indeed, organisms that produce waste products do so without much thought about what happens to the waste. Until recently, the evolution of technological systems has