It is sometimes difficult to accept the proposition that past or sunk costs are irrelevant to decisions. Consider the ticket you have to a major football game in December. After getting the ticket, you learn that the game will be on TV, and you really prefer to watch the game in the comfort of your warm home. Does your decision about attending the game or watching it on TV depend on whether you were given the ticket for free or you paid €80 for it? What does this tell you about a manager’s decision to replace a piece of equipment?