The Economic Way of Thinking 13th Edition by David Prychitko, Peter Boettke, Paul Heyne

Exercise 8

The economist's rule, "sunk costs are irrelevant," is like a string around your finger. It reminds you to consider only marginal costs, but it cannot identify the marginal costs. That requires informed judgment. You could sharpen your judgment by trying to enumerate and assess the marginal costs of retaining or not retaining your college apartment over the summer vacation. Try to calculate the minimum rental from subleasing that would persuade you to retain it for fall reoccupancy.