While the economic damage to forests from air pollution cannot yet be quantified, financial losses from reduced crop yields have been estimated carefully. The most recent and complete analysis shows that ozone is causing extensive agricultural losses that reducing current ozone levels by 40 percent would lead to a $3.5 billion (1987 dollars) annual benefit in increased yields for eight crops. If all affected crops were considered, the benefits would, of course, be much larger.

As for health benefits, deciding how much money pollution reduction is worth is a difficult task. According to one estimate of ozone's effects, controls strong enough to simply meet the current primary ozone standard would yield benefits of $2.6 billion a year nationwide in reduced health risks.

Visibility degradation from air pollution also has high costs. EPA estimates the benefits of improved visibility at $700 million per year in the East from meeting current standards for SO2, while other researchers estimate benefits from meeting current particulate and sulfur dioxide standards at $500 million per year just for California's four major air basins. Some uncertainties persist in these estimates and the benefits are not as readily calculable as are the costs of pollution reduction, but the losses are nonetheless real.