Modern Medicine and the 20th Century Decline in Mortality: Evidence on the Impact of Sulfa Drugs

This paper studies the contribution of sulfa drugs, a groundbreaking medical innovation in the 1930s, to declines in U.S. mortality. For several often-fatal infectious diseases, sulfa drugs represented the first effective treatment. Using time-series and difference-in-differences methods (with diseases unaffected by sulfa drugs as a comparison group), we find that sulfa drugs led to a 25 to 40 percent decline in maternal mortality, 17 to 36 percent decline in pneumonia mortality, and 52 to 67 percent decline in scarlet-fever mortality between 1937 and 1943. Altogether, they reduced mortality by 2 to 4 percent and increased life expectancy by 0.4 to 0.8 years. We also find that sulfa drugs benefited whites more than blacks.