Murphy issued the challenge to Krugman in October 2010. The debate will focus on the Austrian Business Cycle Theory versus the Keynesian Business Cycle Theory. In order to place pressure on Krugman to accept the challenge, Murphy organized a fundraiser to raise $100,000 for the Fresh Food Program in New York City.  The funds would only be sent if Krugman actually engaged in a debate with Murphy. A website (KrugmanDebate.com, now defunct) and several YouTube videos were created in order to spread the news about the debate.
In June 2012, Paul Krugman, referring to the challenge, declined to participate in "circuses" as opposed to a serious debate.
As of March, 2013, over $106,000 have been raised. Murphy has reiterated his challenge, pointing out that Krugman debated Ron Paul in order to promote his book (Krugman explained that he did that to get more readers to see all the data and facts, which may be lost in a televised debate).
- KrugmanDebate.com, official website of the debate.
- Robert Murphy, "My Debate Challenge to Paul Krugman", Mises Daily, Oct. 28, 2010
- Murphy-Krugman Debate v3 (video)
- Heed the Judge (video)
- Paul Krugman. "Paul Krugman Weighs In" (audio, from about 20:00), The Brian Lehrer Show, June 04, 2012. Referenced 21-03-2012.
- ThePoint Fundraising page Murphy-Krugman Debate[dead link], referenced 2011-02-23.
- Robert Murphy. "Krugman Debate Update" (video), published on 18 Mar 2013. Referenced 21-03-2012.
- Paul Krugman. "On the Uselessness of Debates", The Conscience of a Liberal (Paul Krugman's blog with The New York Times), May 1, 2012. Referenced 21-03-2012.
- Robert P. Murphy. "Krugman Debate Update", personal blog, posted 06 Jul 2013. Referenced 05-09-2013.