SomeCrusader - Two Keynesians are going for a walk when they happen across a dog turn lying next to the sidewalk. The first says to the second, "I'll pay you $1000 to eat that". The second agrees, eats the dog turd and accepts the $1000.
A few minutes later they come across another dog turd. This time it is the second Keynesian who offers $1000 to the first if he eats it. The first agrees, eats the dog turd and gets his $1000 back.
After the walk the first Keynesian says to the second, "You know, I don't think that was such a good idea. Now we're both sick and neither of us is any richer".
The second replies, "What are you talking about? We created two jobs and increased the GDP by $2000!"