An economics professor and a Yankee farmer were waiting for a bus in New Hampshire. To pass the time, the farmer suggested that they a game. “What kind of game would you like to play?” responded the professor. “Well,” said the farmer, “how about this: I’ll ask a question, and if you can’t answer my question, you give me a dollar. Then you ask me a question and if I can’t answer your question, I’ll give you a dollar.” “That sounds attractive,” said the professor, “but I do have to warn of something: I’m not just an ordinary person. I’m a professor of economics.” “Oh,” replied the farmer, “In that case we should change the rules. Tell you what: if you can’t answer my question you still give me a dollar, but if can’t answer yours, I only have to give you 50 cents.” “Yes,” said the professor, “that sounds like a fair arrangement.” “Okay,” said the farmer,” Here’s my question: what goes up the hill on seven legs and down the hill on three legs?” The professor pondered this awhile and finally replied. “Gosh, I don’t know…what does go up the hill on seven legs and down the hill on three legs?” “Well,” said the farmer, “I don’t know, either. But if you give me your dollar, I’ll give you my 50 cents!”