Not exactly a joke, but I find it funnier than I find most cow jokes, so...

The Two Cow System
Socialism: You have two cows. You keep one and give the other to your neighbor.
Communism: You have two cows. The Government takes both and shares the milk with you and your neighbor.
Fascism: You have two cows. You give the milk to the government and they sell it back to you.
Nazism: Government shoots you and takes both your cows.
Capitalism: You have two cows. You milk them and pour the lot down the drain to keep the price up.
Sadism: You have two cows. You shoot them both and drown yourself in the milk.
Apartheid: You have two cows. You give the black cow's milk to the white cow to drink and don't milk the white cow.
Welfare State: You have two cows. You milk them and give them the milk to drink.
Anarchism: You have two cows. The cows shoot you and milk each other.
Bureaucracy: You have two cows. You fill in 17 forms in triplicate and you don't have time to milk them.
United Nations: You have two cows. Russia vetoes the farmer from milking them. Britain and France veto the cows from milking the farmers. USA abstains.
Idealism: You have two cows. You marry and your wife milks them.
Realism: You have two cows. You get married and you still milk them.
Common Sense: You have two cows. You sell one and buy a bull!

More can be found here: What Would You Do With 2 Cows (I love the various corporation ones )