Luke is finally tall enough to go on the rollercoasters and Disneyland, but Phil may be at the age where he can’t handle that pressure. The self-proclaimed “King of Rollercoasters” visibly diminishes as Luke seems to be unfazed by the G-force. While each ride adds a bit of additional joy to Phil’s overall utility, the marginal cost is clearly increasing as he continues to ride each ride. It’s not long before Phil’s marginal cost outweighs the marginal benefit of one more ride.
See more: decreasing returns, diminishing marginal returns, increasing marginal cost, marginal utility, marginal benefit, marginal cost, negative returns, utility, utility maximization