paul polman of unilever is a great example.ill expand the revenue and half the environmental footprint. leaders that challenge themselves and their organizations to create economic value, while thinking hard about the negative externalities of business and minimize negative externalities, are the types of leaders that will set a new example for what business needs to be. we are very fortunate. we have examples leaders are showing that way. we are trying to study those examples, trying to make sure we inspire our students to think about that. we are also very lucky that one of the great surprises i have had as dean of harvard business school is that our graduates have always done very well in business. but what has been amazing is to see how many of our graduates are so devoted to social enterprises. if you think about the great hospitals, great universities, charter schools, we are seeing business leaders devote themselves to making these institutions better as well, not just as philanthropists, but by actually bringing managem