Oh yeah? What about when the textbook dogma is contradicted by the data -- both historical and statistical? Here is the comment Sandwichman submitted at the INET site:
In a Sunday Review article at the New York Times over the weekend, Professor Edward Glaeser of Harvard invoked the "lump of labor" fallacy in support of the "counterintuitive" notion that "the forever work life of older Americans may turn out to be a good thing for young workers."
The idea is not only "counterintuitive." It's a fossil of magical thinking from the 18th century. Glaeser's bogus fallacy claim has been shown to be itself a fallacy by no less than A.C. Pigou, Maurice Dobb and (more generally) by J.M. Keynes's father, John Neville Keynes. Yet it gets taught by the likes of Glaeser, Mankiw (who sneered at Albert Einstein for committing the bogus fallacy) and... even Professor Paul Krugman of Princeton:
Economists call it the "lump of labor fallacy." It's the idea that there is a fixed amount of work to be done in the world, so any increase in the amount each worker can produce reduces the number of available jobs. (A famous example: those dire warnings in the 1950's that automation would lead to mass unemployment.) As the derisive name suggests, it's an idea economists view with contempt, yet the fallacy makes a comeback whenever the economy is sluggish.Last May I wrote an open letter to Professor Krugman advising him of the documented falsity of the fallacy claim. I received no reply. The letter, posted at my blog, has received over 2,000 views.
PROVIDE CONTEXT: the "fallacy" claim is based on unrealistic assumptions of no transaction costs, reversible time and total indifference to working conditions. Moreover, it's origin is in pre-industrial economic thought influenced by the conceptual framework of alchemy (which in itself is not necessarily a bad thing -- see Isaac Newton, for example -- but it needs to be tempered with a good dose of skepticism).
BUILD TRUST: I have written to Professor Glaeser on two occasions regarding the fraudulence of the fallacy claim but have received no reply. I have also received no reply from Paul Krugman. I have written two published articles debunking the fallacy claim, one a chapter in an anthology textbook and another in a peer reviewed journal and no one has responded to my critique -- they just keep repeating the bogus claim.
ADDRESS DISTRIBUTIONAL ISSUES: The lump-of-labor fallacy claim is, in effect, an argument from authority that distributional issues don't count.
ADOPT SOME HUMILITY: When is that going to happen? In my lifetime?