The article discusses how surveys can be used to determine the value people place on public goods like clean air and wilderness areas. The researchers suggest that the contingent valuation method is the best way to do this. They explain how this method works, compare it to other ways of measuring benefits, and highlight the importance of addressing errors and biases in the process. The key finding is that by carefully applying the contingent valuation method, valid information on the value of public goods can be obtained.