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, which happens to be...

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.