Rodrik distinguishes between the limitations of what economists really know and thus what they tell graduate students, and the stripped-down version offered to undergraduates because, apparently, all the qualifications are "deemed to be in appropriate (or dangerous) for the general public". (I wrote a bit about this theme in an earlier blog.) Instead, what economists are apt to do is to choose from the plethora of models available ones "that best accord with their own personal ideologies".
the economics we need is of the “seminar room” variety, not the “rule-of-thumb” kind. It is an economics that recognizes its limitations and knows that the right message depends on the context. Downplaying the diversity of intellectual frameworks within their own discipline does not make economists better analysts of the real world. Nor does it make them more popular.