Yes, but here’s the thing: you don’t have a monopoly over your potato farming method. Lots of new farms are built, and the more that do, the more the average price of a potato drops. Your expected return starts to drop. Yours - and everyone else’s - profit margins get squeezed.

Investors begin to refuse to build new potato farms because a return on their investment gets worse whenever anyone decides to build a new farm.

But the people need potatoes and more potato farms! The government issues an incentive scheme to guarantee a minimum price for each potato sold. Potential farm owners bid against each other for the lowest price, but it means they can build a farm and expect to break even.