Barkley sees no harm in using the AS/AD device to explain stagflation. And David claims that we should conceive of AS/AD and IS-LM as didactic devices to help teachers explain policy. In both cases the idea of simplicity is invoked as a justification, although with David it is not completely clear whether he supports these devices or whether he is just reporting that the number one text uses them. It is worth remembering that this thread began with an observation that it is the textbooks that were responsible for the myth described in the title. It seems to me that Barkley and David are, at least implicitly, supporting the idea that textbooks have a legitimate use in perpetuating myths. It also seems me that to say that AS/AD should be used in econ textbooks is analogous to saying that genesis theory should be used in high school biology textbooks to explain the history of life on earth and the diversity of species. It is certainly easier to attribute these to God than to try to teach what scientists have discovered (and not discovered) and how they have done so. We can explain stagflation, the effects of tax cuts, etc. in many ways. To explain it with AS/AD and IS-LM diagrams that students are unable to comprehend or that they are likely to comprehend wrongly, seems to me inconsistent with the chosen mission of the teacher. It would be better -- and a whole lot more economical -- to teach that macroeconomists are brilliant people who we depend on to help us make policy decisions. After all, if this were not so, how could it be that the great depression has not been repeated, that the U.S. has had 16 years of more or less uninterrupted growth without significant inflation or unemployment, and how the world economy has been growing at an unprecedented clip for half a century? (It goes without saying that no economist I know believes that any of these events are due to the brilliance of macroeconomists who help governments to make policy.) What else could we teach in macro policy? We could teach the history of how politicians and government bureaucrats -- often claiming to follow some economic theory -- have botched the job.Yet they seem to have stumbled into a successful recipe, which is perhaps the way it must always be in a democracy. On this point I would refer the reader again to Robert Mundell's interpretation of the 20th century. Mundell, R. A. (2000) "A Reconsideration of the Twentieth Century." The American Economic Review. 90 (3): 327-340. Hopefully, Kevin has chose something better than what we have typically seen. Pat Gunning