T HAS BEEN THE PRINCIPAL THRUST OF THIS TEXTBOOK that a truly sustainable economy can be achieved only when both traditional as well as green inves-

tors can agree on processes and products that are both profi table and sustainable. [See Figure 26-1. ] This does not mean, however, that there is no room for investment opportunities that appeal largely to green investors. In fact, the emergence of the phenomenon of social entrepreneurship signals the viability of this option. The social enterprise is a broad and somewhat amorphous category, as it includes not only traditional nonprofi ts but also organizations that can be profi table but have as their principal, if not exclusive, focus the advancement of social and environmental objectives. In many cases, any profi ts that might be generated are reinvested in order to advance the particular social goals of the organization. Another way of viewing the strategic functioning of this type of entity is to see it as maximizing the achievement of social goals with a nonnegative profi t constraint. This chapter fi rst provides a brief review of the state of social enterprise in the United States and the United Kingdom, as well as diverse models of social enterprise globally, and then summarizes some of the more common metrics for measuring the success and impact of social enterprise.