"[A]uthors Ernst Berndt, Susan Busch, and Richard Frank have created a price measure for the treatment of one major illness: depression. One in ten American suffers from major depression. The authors identify therapeutically similar treatment bundles, based on an intensive review of the clinical literature. They also tap into a medical claims database of almost half a million lives, annually from 1991 to 1995. The price indexes they calculate are based on transactions prices rather than list prices; they take into account treatment episodes, quality, and expected outcomes; and, finally, they use time-varying expenditure weights.