His books include The Next Economy, The Ecology of Commerce, and (with Amory Lovins and Hunter Lovins) Natural Capitalism. The latter two were influential in the development of the theory of natural capital and of the human economy as a service economy based on nature's services. He was one of the first to suggest a price of Earth could be calculated based on assumptions imposed by a given political economy.
As of 2003, he has been promoting principles of what he calls the restorative economy: