There is no point in beating folks like Robert Barro “and all the other Lucases and Famas and Boldrins and Cochranes” and remaining loudspeakers of the mainstream.#1 This only distracts from the fact that the major approaches ― Walrasianism, Keynesianism, Marxianism, Austrianism ― are mutually contradictory, axiomatically false, materially/ formally inconsistent, and that all got the foundational economic concept profit wrong. In other words, there is NO such thing as scientifically valid economics.
“In order to tell the politicians and practitioners something about causes and best means, the economist needs the true theory or else he has not much more to offer than educated common sense or his personal opinion.” (Stigum)
The fact is that economists do not have the true theory: after 200+ years, economics is a failed/fake science or what Feynman called a cargo cult science.#2 The vast majority of economists are NOT scientists but political agenda pushers. Economics is NOT an integral part of science but of the Circus Maximus.
To be sure, the Barros, Lucases, Famas cannot be taken seriously, but neither can the Krugmans, Thomases, and DeLongs.#3
#1 Stop beating mainstream economics ― it is long dead
#2 What is so great about cargo cult science? or, How economists learned to stop worrying about failure
#3 Trust in economics as a science?