There's an old joke that explains world religions
through the example of "Shit happens."
This is actually a very useful tool for understanding 
different world religions. I think that it's instructive. 
So I thought that maybe we could attempt to do 
something similar to this in economics.
The basic economics version, of course, is the 
difference between microeconomics and macroeconomics.
There's actually been a tremendous amount of progress in macroeconomics 
over the last century, so if you want the macroeconomics version...
There are of course other fields in economics.
Then there are a couple of fan submissions.
 I told folks that I would give them a free copy of my Cartoon Macroeconomics 
book if they submitted something that I used during the show tonight.
…which is actually a brilliant definition
that no one will be able to use in class ever.
That is a very in joke among the 
environmental economics crowd.
