Answer: Over 80% of eggs in the United States are produced in a factory "farm" setting – cages, no outside time, artificial light...the stuff of very dark Netf/lix documentaries. These are called commodity eggs, and they're the ones that end up in "store brand" cartons, priced around a dollar a dozen (depending on the time of year and year itself, of course). No single farm sets the price for these eggs; they're priced according to a commodity index similar to wheat or milk (it's called Urner Barry if you feel inclined to Goo/gle).