Jon Reisman
One of my favorite courses was demography, the study of human populations. Demographers draw on statistics and a broad swath of both the natural and social sciences, including economics, sociology, geography, political science, biology, psychology, and medicine. Demography starts with a deceptively simple mathematical identity: Change in Population= Births - Deaths + Net Migration. Therein lie some of the most sensitive and freedom consequential policy areas: fertility, mortality, and immigration/emigration.