2014-12-30
Explanation
The Joke
A woman declares that "Economics is stupid because it assumes people behave rationally." She backs this up by saying: "I mean, look at me! I'''m a person and I'''ve never read a single book on economics, yet I'''m positive the entire field is founded on a single, obviously false premise!" A man asks her to explain, and she identifies herself as a first-year physics student with delusions of grandeur. The man responds, "Lucky guess."
The Humor
The joke is a self-defeating argument. The woman claims that economics is wrong because it assumes rational behavior, but in doing so, she demonstrates exactly the kind of irrational behavior she is describing -- making sweeping, confident claims about a field she has never studied. She is living proof that people do not always behave rationally, but ironically, she is the one being irrational, not the economists she is criticizing. The additional layer of humor comes from her being a first-year physics student, playing on the stereotype that physics students (and STEM students in general) often have an inflated sense that their field is superior and that they can dismiss entire other disciplines without understanding them. The man'''s "lucky guess" implies this is such a common type that she is immediately recognizable.