Air pollution officials in California’s Central Valley have opened a new front in the war against urban sprawl, and regulators and environmental advocates throughout the state are watching closely. Starting in March 2006, the San Joaquin Valley Air Pollution Control District in California became the first regulatory body in the country to impose fees on new residential and commercial development specifically focused on reducing air pollution. Critics argue that this is an ineffective way to control pollution and will mainly drive up housing prices, making housing less affordable for the poor. Is this policy a good idea?