During dinner my friends debated about what kind of egg one should buy. Some says that big (XL/jumbo) eggs is painful for hens. People should buy small eggs. One of the first-year student speaks up
If everyone goes to buy small eggs, producers do notice that large eggs don’t sell well. Then hens that lay large eggs will lose their commercial value. Farmers will kill them and replace them with hens that lay small eggs. By buying large eggs yourself, you are protecting the jobs and the lives of hens that lay large eggs.
This person really did price theory well…