1620-1674

English statistician generally credited as the founder of scientific demography. A founding member of the Royal Society, Graunt began studying London death records dating back to 1532. He noticed a number of patterns, which he discussed in Natural and Political Observations... made upon the Bills of Mortality (1662), classifying death rates according to cause, and identifying overpopulated conditions as a mortality-increasing factor. He also developed one of the earliest life-expectancy charts, which was based on his studies of survivorship. Graunt's ideas had a profound effect on the demographic efforts of Sir William Petty (1623-1687), and on the mathematical studies of Sir Edmund Halley (1656-1742).