"You have two cows" is the beginning phrase for a series of political

Politics

Politics is a process by which groups of people make collective decisions. The term is generally applied to the art or science of running governmental or state affairs, including behavior within civil governments, but also applies to institutions, fields, and special interest groups such as the...

 joke

Joke

A joke is a phrase or a paragraph with a humorous twist. It can be in many different forms, such as a question or short story. To achieve this end, jokes may employ irony, sarcasm, word play and other devices...

 definitions.
"You have two cows" jokes originated as a parody

Parody

A parody , in current usage, is an imitative work created to mock, comment on, or trivialise an original work, its subject, author, style, or some other target, by means of humorous, satiric or ironic imitation...

 of the typical examples used in introductory-level economics

Economics

Economics is the social science that analyzes the production, distribution, and consumption of goods and services. The term economics comes from the Ancient Greek from + , hence "rules of the house"...

 course material. They featured a farmer in a moneyless society who uses the cattle he owns to trade with his neighbors. A typical example is: "You have two cows; you want chickens; you set out to find another farmer who has chickens and wants a cow".