“Murder on the Sidelines.” Marginal thinking is a major economic principle. This has very little effect and a small part in the plot but it is referenced in the title. It's about making the decision to add one more at a time: "Would it benefit me to add one more?" » “If I added one more, would that be too much?” “What if I removed one?” These questions are questions that one would ask when thinking on the margins. Rationality is probably one of the biggest debates in economics. Whether a decision is rational or irrational. If I were to make a rational decision, it would be more beneficial to me than any other choices I could have chosen from. This is how Professor Henry Spearman solves the murder case. All suspects are proven guilty or innocent based on the decisions they make. If it is a rational decision, then the suspect is considered innocent. If it is an irrational decision, then the suspect is considered