It is...a fact that within mainstream economics internal validity is everything and external validity nothing. Why anyone should be interested in that kind of theories and models is beyond my imagination. As long as mainstream economists do not come up with any export-licenses for their theories and models to the real world in which we live, they really should not be surprised if people say that this is not science, but autism!Of course, economic models, like everything else in today's world, are under the control of our capitalist masters. If they were to really test these models and theories, they would fail miserably. They have to make up all kinds of lies, fudge numbers, and keep repeating the mantra that "there is no alternative" to support their system of capitalism. Hence, their supporting theory and models have become a mythology that only capitalists really believe in, or a dogma that capitalist priests keep preaching after it has long failed to explain anything happening in the real world.
Studying mathematics and logics is interesting and fun. It sharpens the mind. In pure mathematics and logics we do not have to worry about external validity. But economics is not pure mathematics or logics. It’s about society. The real world. Forgetting that, economics is really in dire straits.
We’ve lived so long under the spell of hierarchy—from god-kings to feudal lords to party bosses—that only recently have we awakened to see not only that “regular” citizens have the capacity for self-governance, but that without their engagement our huge global crises cannot be addressed. The changes needed for human society simply to survive, let alone thrive, are so profound that the only way we will move toward them is if we ourselves, regular citizens, feel meaningful ownership of solutions through direct engagement. Our problems are too big, interrelated, and pervasive to yield to directives from on high.
—Frances Moore Lappé, excerpt from Time for Progressives to Grow Up