I’d say one of the best arguments is the years 2008-2010.
Unfortunately, he has a logical mind like me and simple answers like that won't suffice.
I was thinking about something along these lines:
First, get him to agree that a capitalist economy basically boils down to private sector jobs. Then ask if government spending creates or destroys private sector jobs.
Another point to make would be that the government produces nothing (except debt, I suppose). Also, government has no money other than what they loot from the private sector.
Keynes was a queer fellah who happened to be a genious in the field of economics. He is referred to as the father of economics. But you need to look at QE2, for example. He believed in increasing the money supply to level out the economy. But as you will soon see, when you increase the money supply with low unemployment is causes stagflation. You will soon see gas and other products increase in price.
I’m not an economist but am a returning MBA student. The kid is a liberal obviously. There are much smarter freepers here on this matter, but that’s my take.