Explain what happens to the official measure of GDP in each of the following situations.
a. Air quality improves significantly throughout the United States, but there are no effects on aggregate production or on market prices of final goods and services.
b. The U.S. government spends considerably less on antipollution efforts this year than it did in recent years.
c. The quality of cancer treatments increases, so patients undergo fewer treatments, which hospitals continue to provide at the same price per treatment as before.