Basically, nobody knows anything[1]. But if everyone were to admit that, there would be no basis on which to conduct policy. → Chaos/arbitrariness/incoherence (over time and sectors)
So people make up and promote a narrative (bullshit story) and if enough people believe / are made to believe in it, then you have a basis for relatively stable and coherent policy regime.
This interpretation of economics (as a field) is consistent with the history of economic ideas. No economic ideas are ever discarded or disproven (the very antithesis of science if you will). As the Economist aptly put it: "Macroeconomic arguments tend not to produce winners and losers: only those with more in- fluence and those with less."[2]
That's why economics (the field) is really less about economics (the substance) but about politics and power.
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[1] Hyperbolically speaking, of course, and aimed in particular at macro- and monetary economists. There are some nice results but they apply, as far as I could tell, mostly to smaller settings, not the aggregate economy.
[2] The Economist. Free exchange: Magic or logic? page 69, Mar 16 2019.