Alchian–Allen effect

The Alchian-Allen effect is like the peanut butter and jelly effect. It's a way of understanding how changes in one thing can lead to changes in another. Peanut butter and jelly go together - if you add more jelly, you usually want to add more peanut butter so that the two things are balanced. Similarly, with the Alchian-Allen effect, if the price of one thing goes up, like the price of peanut butter, the amount of something else, like jelly, might go down so everything is balanced.