Great example of the concept of equilibrium that economist talk about.

For those who don’t know, equilibrium is an economic balance in which no individual would be better off doing something different. Basically an equality of supply and demand.

In my macroeconomics textbook written by Krugman and Wells they give the example of a busy supermarket when a new line opens up. People aren’t told to shift the sizes of the lines in the most efficient way; they just act out of their own interest to get into the quickest line causing the lines to even out equally. You don’t need to know the details of what happens when that new line opens up, how shoppers rearrange, who moves ahead of whom; what you need to know is any time there is a change, the situation will move to an equilibrium.

• Markets usually reach equilibrium via changes in prices, which rise or fall until no opportunities for individuals to make themselves better off remain.

• the fact that markets move toward equilibrium is why we can depend on them to work in a predictable way