Disagreement with the world's environmentalist wackos doesn't mean that one is for dirty air and water, against conservation and for species extinction. Dr. Richard Stroup, Montana State University professor of economics and senior associate of the Center for Free Market Environmentalism, explains commonsense approaches to environmental issues in his new book, "Eco-nomics: What Everyone Should Know About Economics and the Environment." Stroup starts out with the first lesson of economics: There's scarcity. That means more of one thing means less of another. California's San Bernardino County was just about ready to build a new hospital. That was until the U.S....