David Henderson, editor of the Concise Encyclopedia of Economics and a research fellow at Stanford's Hoover Institution, talks with EconTalk host Russ Roberts about when and why economists disagree. Harry Truman longed for a one-armed economist, one willing to go out on a limb and take an unequivocal position without adding "on the other hand...". Truman's view is often reflected in the public's view that economic knowledge is inherently ambiguous and that economists never agree on anything. Henderson claims that this view is wrong--that there is substantial agreement among economists on many scientific questions--while Roberts wonders whether this consensus is getting a bit frayed around the edges. The conversation highlights the challenges the everyday person faces in trying to know when and what to believe when economists take policy positions based on research. Is it biased or science?