My question to the Undercover Economist is simple. 'On what do you base your assertion that Adam Smith never visited a pin factory?'Now Marshall Jevons at The Bayesian Heresy offer this explanation;
Harford refers to David Warsh's book, chapter 3 in the references. It is actually chapter 4.So according to Jevons, it is David Warsh who may be at fault. On checking my copy of Knowledge and Wealth of Nations Warsh does make this claim. So I guess the question now is, What is Warsh's evidence for his claim?"These first three chapters and the plan of the book provided the whole kernel of what we would call today a theory of growth. Much stress has been laid over the years on the significance of the description of the pin factory. In fact Smith never visited one. Apparently he based his account on an article in an encyclopedia. Never mind that Smith was widely traveled and sharply observant everywhere he went. His failure to expend much shoe-leather in this case has occasionally been cited to discredit him. Such cavils entirely miss the point."No Tim Harford didn't lie, he was just quoting David Warsh.
-Knowledge and Wealth of Nations, p. 40 ( you can go to Amazon’s search inside the book feature)
Update: Gavin Kennedy has brought things up to date at his Adam Smith Lost Legacy blog, see the posting David Warsh is Named as the Source for the Allegation that Adam Smith Did Not Visit a Pin Factory.
Update 2: See The game is up? for a summary of David Warsh's response to Kennedy.