Murphy is research assistant professor with the Free Market Institute at Texas Tech University. He has been a visiting assistant professor at Hillsdale College, and a visiting scholar at New York University. He has been affiliated with Laffer Associates, the Pacific Research Institute, the
Institute for Energy Research (IER) as the senior economist focusing on climate change, the
Independent Institute, the
Ludwig von Mises Institute, and the
Fraser Institute in Canada. Murphy has written books such as
Choice: Cooperation, Enterprise, and Human Action (Independent Institute, 2015),
Primal Prescription with Doug McGuff, MD regarding healthcare in the United States, and
Lessons for the Young Economist (Mises Institute 2010). He has written study guides to works of
Ludwig von Mises and
Murray Rothbard. Murphy has been criticized by economists
Brad DeLong and
Paul Krugman for predicting that the
quantitative easing practiced by the
Federal Reserve in the late 2000s would create high inflation by 2013, which did not materialize by that time. In 2013 Murphy challenged Krugman to a debate and unnamed supporters of Murphy promised to donate $100,000 to a charity if Krugman would debate Murphy on economic policy issues. A promotional website was established for the challenge. In response to a radio show caller, Krugman rejected the proposed debate, saying that the subject “is not something to be settled by public circuses".
Environmental policy Murphy has stated related to climate change that, "Many economists favor some form of government penalty on CO2 emissions because of the threat of climate change. However, the steps in the argument—going from computer simulations to a specific, numerical tax on economic activity today—are riddled with uncertainties". Murphy has additionally been quoted as saying, "Given the large uncertainties at each major step of the case for reliance on a
carbon tax, economists should reconsider their current support for such a policy". Additionally, Murphy has been quoted as stating, "I reject the
peak oil theory insofar as it refers to technological limits on human ingenuity". ==Religious views==