You quote Popper affirmatively: “And try to construct alternative theories — alternatives even to those theories which appear to you inescapable; for only in this way will you understand the theories you hold.”
Blaug told us: “The moral of the story is simply this: it takes a new theory, and not just the destructive exposure of assumptions or the collection of new facts, to beat an old theory.” (1998, p. 703)
Schumpeter, too, told us that debunking and complaining is not enough: “If we feel misgivings ..., all we have to do is to start appropriate research. Anything else is pure filibustering.” (1994, p. 577)
Everybody knows by now that standard economics has failed to produce a formally and materially consistent theory. This is the open door for Heterodoxy. All that has to be done is, as Popper said, to go into constructive mode.
And here is how the Paradigm Shift is put into effect “When we assemble the facts of a definite, more-or-less comprehensive field of knowledge, we soon notice that these facts are capable of being ordered. This ordering always comes about with the help of a certain framework of concepts... The framework of concepts is nothing other than the theory of the field of knowledge. ... If we consider a particular theory more closely, we always see that a few distinguished propositions of the field of knowledge underlie the construction of the framework of concepts, and these propositions then suffice by themselves for the construction, in accordance with logical principles, of the entire framework. ... The procedure of the axiomatic method, as it is expressed here, amounts to a deepening of the foundations of the individual domains of knowledge — a deepening that is necessary for every edifice that one wishes to expand and to build higher while preserving its stability.” (Hilbert, 2005, pp. 1107-1109)
After more than 200 years of failure, orthodox economists urgently need a heterodox demonstration of how genuine scientists work. The great economist and methodologist J. S. Mill, of course, knew this long before Popper: “Doubtless, the most effectual mode of showing how the sciences of Ethics and Politics may be constructed, would be to construct them ...” (2006, p. 834)
Blaug, M. (1998). Economic Theory in Retrospect. Cambridge: Cambridge University Press, 5th edition.
Hilbert, D. (2005). Axiomatic Thought. In W. Ewald (Ed.), From Kant to Hilbert. A Source Book in the Foundations of Mathematics, Vol. II, 1107–1115. Oxford, New York: Oxford University Press.
Mill, J. S. (2006). A System of Logic Ratiocinative and Inductive. Being a Connected View of the Principles of Evidence and the Methods of Scientific Investigation, Vol. 8 of Collected Works of John Stuart Mill. Indianapolis: Liberty Fund.
Schumpeter, J. A. (1994). History of Economic Analysis. New York: Oxford University Press.
Related 'Towards the true economic theory' and cross-references Constructive Heterodoxy.