A fresh Nobel Prize laureate in economic sciences Paul Romer published three years ago an interesting short paper “Mathiness in the Theory of Economic Growth”. His main assertion (which granted him with colleagues’ reactions such as “don’t make waves“) was that economists tend to deliberately use math in misleading ways:
“The style that I am calling mathiness lets [economics’] academic politics masquerade as science. Like mathematical theory, mathiness uses a mixture of words and symbols, but instead of making tight links, it leaves ample room for slippage between statements in natural versus formal language and between statements with theoretical as opposed to empirical content. (p. 89)
Mathiness could do permanent damage because it takes costly effort to distinguish mathiness from mathematical theory… The market for mathematical theory will collapse. Only mathiness will be left. It will be worth little, but cheap to produce, so it might survive as entertainment. Economists have a collective stake in flushing mathiness out into the open.” (Romer 2015: 90)
This reminded me three beautifully clever and witty quotes by Joan Robinson, Robert Heilbroner and Paul Samuelson.
Romer, however, went on to “make waves” and air his discontent with economics. In 2016 he gave a lecture titled “The Trouble with Macroeconomics“, whose abstract states that:
“For more than three decades, macroeconomics has gone backwards. The treatment of identification now is no more credible than in the early 1970s but escapes challenge because it is so much more opaque. Macroeconomic theorists dismiss mere facts by feigning an obtuse ignorance about such simple assertions as “tight monetary policy can cause a recession.” Their models attribute fluctuations in aggregate variables to imaginary causal forces that are not influenced by the action that any person takes. A parallel with string theory from physics hints at a general failure mode of science that is triggered when respect for highly regarded leaders evolves into a deference to authority that displaces objective fact from its position as the ultimate determinant of scientific truth.”
Romer concludes his lecture, stressing that:
“The trouble is not so much that macroeconomists say things that are inconsistent with the facts. The real trouble is that other economists do not care that the macroeconomists do not care about the facts. An indifferent tolerance of obvious error is even more corrosive to science than committed advocacy of error.”