Putting a low price on valuable environmental resources is a phenomenon that pervades modern society. Agricultural water is not scarce in California; it is underpriced. Flights are stacked up on runways because takeoffs and landings are underpriced. People wait for hours in traffic jams because road use is unpriced. People die premature deaths from small sulfur particles in the air because air pollution is underpriced. And the most perilous of all environmental problems, climate change, is taking place because virtually every country puts a price of zero on carbon dioxide emissions.

"The Pope & the Market," The New York Review of Books, October 8, 2015