Final answer:
Theodore Schultz conducted a study examining the opportunity cost of post-secondary education, which considers not just the direct costs but also the value of alternative activities forgone, such as employment.
Step-by-step explanation:
The study examining the opportunity cost of post-secondary education was conducted by Theodore Schultz. Opportunity cost represents the value of everything you must give up to acquire something else. In context to post-secondary education, opportunity cost includes not only the tuition, fees, and books, but arguably more importantly, the value of forgone alternatives such as working and earning money during the time spent in educational pursuits. This concept is related to the economic theories explored by economists like Friedrich Hayek, Milton Friedman, John Maynard Keynes, and Adam Smith, who have all contributed to the understanding of the free enterprise system in the U.S. Moreover, the personal decision-making process, as emphasized by opportunity cost, reflects the trade-offs people must consider, affecting both individual and wider economic circumstances.