FEUDALISM: You have two cows. Your lord takes some of the milk.
PURE COMMUNISM: You have two cows. Your neighbors help you take care of them, and you all share the milk.
PURE DEMOCRACY: You have two cows. Your neighbors decide who gets the milk.
FASCISM: You have two cows. The government takes both, hires you to take care of them and sells you the milk.
VALVE'S POTATO SCAM: As a honest buyer, you are entitled to one cow. The cow is already a grown adult, healthy and ready to be milked. However, Gabe Newell takes it hostage and will release it only after a certain arbirtary date. Moreover, he says that if you want it back sooner you'll have to buy another (mangy, haggard and retarded) cow from one of Gabe's friends, pump lots of undrinkable milk for hours on end and then give it to Gabe as a sign of loyalty and goodwill. Depending on star alignment and what the weather is like, Gabe will decide if it's enough or not.