My students have applied the same idea in their own lives, discovering that they’re better off assigning the task of cooking dinner to whichever roommate doesn’t have a big paper due, rather than to the best cook. (And during exam week, they assign the task to the local pizzeria.)

Many of their parents probably used the same idea years earlier when deciding who should get up at 3 a.m. when the baby fusses, discovering that the opportunity cost is lower for whoever can be more productive the next day, even when sleep deprived.

The same idea guides much of the business world, explaining why your dentist rarely cleans your teeth, your vet rarely weighs your pup and law partners rarely draft motions.

In each case, the question about how best to allocate tasks rests on the same calculation, which involves identifying the best alternative use of your time. This approach can even guide shopping decisions. After all, when you’re deciding whether to buy pre-cut vegetables, you’re effectively asking whether to assign the task of chopping your veggies to yourself or someone else.

Start thinking this way and you’ll quickly see that the ideas that guide your everyday decisions also propel international trade, which is why American engineers design iPhones, while foreign workers — who have fewer alternative opportunities — do the laborious work of putting them together. By assigning tasks this way, Americans have gotten cheaper iPhones, and Chinese and Indian consumers have gotten greater access to advanced technology.

Teaching useful economics, this approach to teaching tweaks the incentives facing students. As they discover that economic ideas are relevant to their personal and professional lives, it becomes more likely that the benefits of engaging with economics will outweigh the costs.

It shouldn’t be surprising that a field that traditionally focused on the production decisions of a mythical widget factory failed to attract many women students. A broader approach to social science is likely to engage a more diverse array of students.