Why prescription drug prices are plunging

Data: Bureau of Labor Statistics; Chart: Courtenay Brown/AxiosAmerica is experiencing its biggest prescription drug price deflation in generations. Why it matters: By one important measure, there is a striking reversal underway for one of health care's most stubbornly expensive necessities amid a major Washington push to lower drug costs.By the numbers: Prescription drug prices fell 0.8% in July and are down 3.1% from a year ago —