Gary Becker, who won a Nobel Prize for applying economic theory to areas like racial discrimination and family life, has died. The University of Chicago said that Becker, 83, had been ill for some time before his death Saturday. Becker held a dual appointment there in the departments of economics and sociology. Like his teacher, Milton Friedman, Becker won both the Nobel Memorial Prize in Economic Science and the Presidential Medal of Freedom. They are the only two to have received both honors. "Professor Becker has shown that economic principles do not just exist in theory," President George W. Bush said in 2007. The University of Chicago honored both men in 2011 by creating the Becker Friedman Institute for Research in Economics. Becker was the first chairman. Becker began his career with The Economics of Discrimination, arguing in 1957 that discrimination hurts both its perpetrators and its victims. In his 1981 A Treatise on the Family, he went on to argue that people tend to have fewer children as their income rises because they invest more in each one and that those children have economic reasons to treat each other more altruistically than they are inclined to -- something that became known as the "rotten kid" theorem. While he was an academic, Becker also wrote a monthly column for Business Week and in 2004 began putting out a blog with Richard A. Posner, a federal appeals court judge and senior lecturer at the University of Chicago law school. Becker grew up in New York City and graduated from Princeton University before doing graduate work at Chicago. The Princeton Alumni Weekly named him No. 11 on a 2008 list of most influential alumni headed by President James Madison and including President Woodrow Wilson, F. Scott Fitzgerald and mathematician Alan Turing.