Supply management only makes some farmers rich.

We have supply management in Canada because farmers and governments recognized that it was hard for farmers to make a living in the marketplace. There’s a paradox that makes food different from other commodities: A really lean season means similarly lean income while a bumper crop floods the market and lowers the price, leading to more lean income. Farmers who own quota in a supply management system typically fare better than farmers who don’t. Also, the price guaranteed by supply management provides Canadians with a price-stable, high-quality source of dairy. Milk prices don’t suddenly spike. Moreover, the system has enabled Canadian farmers to have smaller herds than American farmers where herds are as large as 100,000 cattle. Slowing the growth of big dairy farms has left rural communities with more small farms, which in turn contributes to the richness of rural life that even city people experience when they head to the country.