Molly (Madeline Carroll) and her dad Bud (Kevin Costner) are driving down the road, but Bud is unhappy with egg salad sandwich as a lunch option. Molly quickly points out that they are on a budget and that if he wants to eat better then he needs to drink less beer. This tradeoff can be illustrated with a budget constraint in economics. Given a fixed level of income, the only way to get more (or better) food, is to give up something else.