When I was at Swarthmore, students campaigned for the school to use more renewable energy and switch to Pepsi. At CogoLabs employees requested they stock organic food. This is not unusual: people all over the country are making personal consumption changes and asking institutions they are associated with to do the same.

To a large extent, especially with colleges, it works: student pressure can change institutional policy. These institutions modify their purchasing in ways that are better but cost more. Better in two ways: for the people of the institution and for the world as a whole. There's a spectrum from virtuous energy, where the product is unchanged but produced in a better way, to heirloom foods, which are tastier but mostly only benefit the people eating them.

Both of these benefits can be had more cheaply, however, when bought separately. A university that takes the additional money wind power would cost and donates it to the most effective charity it can find or a cafeteria that buys the tastiest, healthiest food it can without caring whether it is organic does better for its money.

But then there's a question: if we pressured institutions to give to charity instead of changing their consumption, would they? If they wouldn't, it may be that despite the inefficiency of trying to improve the world by paying more for wind power we should still be encouraging them to do it because otherwise the money wouldn't be doing anything globally beneficial at all.