When Tyler and I were writing Modern Principles of Economics, we wanted examples that were modern, specific, and grounded in the real world. That has been a bit of a headache, because we have to update them with every new edition. Our biggest competitor uses the ice cream market as its central example and never has to revise. Smart! But for us, the extra work has been worth it.

We chose the oil market as our central example. Oil is always in the news, and it works really well across a wide range of textbook topics: the elasticity of demand and supply; oligopoly and cartels; the shutdown condition; shocks; expectations, speculation and futures markets; and oil prices have macroeconomic implications that connect micro to macro.

Yes, keeping the examples current takes more work. But when a student sees that the price of crude has surged past $100 a barrel because Iran closed the Strait of Hormuz—choking off 20% of the world’s oil supply—they have the framework to understand what is happening. Supply shock, inelastic demand, expectations and speculation, the macroeconomic transmission to GDP—it’s all right there in the headlines. Try doing that with the ice cream market.

See the Invisible Hand. Understand Your World. It is not just our slogan. It’s our method.