I understand that there's a twitter/facebook meme going around attributing to Buchanan the following line: "Economics is the art of putting parameters on our utopias."
That is not a Buchanan quote. It belongs to none other than our own Dave Prychitko, though Pete claims a version of it with "Praxeology" in for "Economics" is his. Let's just say it was part of the GMU oral tradition at the time. The two things I can say with certainty are that it was not Buchanan and it was not me!
I think I may be responsible for the misattribution to Buchanan. In a lecture in 2006, I attributed that line to him. I linked that around a lot and probably generated the misattribution. At the time, it was Pete who told me that the line was Dave's, so in the published version of that lecture ("Ought Implies Can" in The Freeman), I attributed it to Dave.
Finally, what made me think it was Buchanan was the talk he gave at IHS's 25th anniversary in November of 1986. That talk was excerpted the next day in the Wall Street Journal (November 14, 1986) under the title "Quest for a Tempered Utopia." The last line of that piece makes a similar point, though not in the exact language that Dave and Pete used.
So if you have ever wondered where misattributed quotes begin, now you know at least one. Mea culpa all.