So it is the end of the year and what a stunning year it has been for all sorts of creative story telling inside the economics profession (particularly in its conservative manifestation). I am going to kick this list off with No. 10 and take my readers’ input for the remaining nine.
To my mind the No. 10 has to be the revisionist claim that arguments for free trade are not about jobs but rather some other metric of economic goodness. Empirically when free trade turned out to be a job killer in Canada, especially after the low CDN dollar policy had ended, conservative economists began circulating the missive that free trade was never about jobs but rather X efficiency or some other idea that lacked any empirical test / verification. In idiomatic terms we call this “moving the goal posts to infinity”; in layman’s terms we call this chicken !@#$%^&; in scientific terms we call it proof positive of a degenerating paradigm.
En effet, this has been a banner year for the depths to which conservative economists are willing to plumb in order to rehabilitate that snow plough job which is micro-macro 101. There are many more, I will post one a day until Xmas eve.
Relentlessly Progressive Political Economy 
I’m thinking the lie that poor black people getting loans from the community reinvestment act caused the US financial system to melt-down is a pretty big one.
But yeah, I remember the post-facto shrugs from mainstream economists: WE never said that free trade would bring jobs! jobs! jobs!
(I believe it was “zero inflation” that would bring us economic utopia, but that’s twenty years ago now.)
Yes this one (the one you point to) is part of the big big lie of 2010. Actually the version you are mentioning is its first iteration and was one of the big attempted lies of 2007 and got dismissed as credible fairly quickly though some do trot it out still. It does live on interestingly in two other forms: as part of the austerian morality play and as the origin that the US government is to blame via Fannie and Freddy Mac. One of those two are high on my list. So possibly No. 1 and 2.
Yeah, you could probably quote from Saint Paul on the G.O.P.’s framing of the entire collapse as a result of government meddling in the recent report. It’s been a couple of years, after all, noone really remembers much about the whole thing and why not blame the government and avoid all that uncomfortable tragic complexity….