In his first semester of teaching economics at Purdue, in the fall of 1955, Smith found it a challenge to present basic microeconomic theory to undergraduates. So the next semester, to make the theory more accessible, he ran a market experiment on the first day of class using rules that are laid out in the Experimental Economics entry. Smith, himself a skeptic about how quickly such an artificial market would reach equilibrium, was stunned by the results. More than anything he had learned in graduate school, these results convinced him that free markets work. From 1956 to 1960, he experimented further with various changes in the rules, and in 1962 he published his article on experimental economics.