[Gogmagog]

She is saying,

Economics is not a hard science. People often try to use it as a hard science to "prove" something in the social realm. Those people are using economics as a pseudo-science.

She has made the case before(in other stories) that Economics is more like psychology than physics. While psychology can give useful information, guide treatment, and affect outcomes, it will never be able to "prove" anything about any person.

[cal5k]

Actually, the problem with economics is that it is not enough like psychology. Psychologists generally perform experiments before concocting theories (or at least they conduct them to confirm or invalidate them), whereas economists generally concoct theories and attempt to fit those theories to data that has not been acquired through experimentation.

[Gogmagog]

Economics experiments always seem to tell you exactly how Graduate students in an Ivy-league Econ 503 class would behave in any situation. :P

[jseliger]

City Journal makes this argument too: http://www.city-journal.org/printable.php?id=6330 .