An economic model is a sort of parable. Intuitively, every economist should know this. You lay out assumptions — that is, a framework for a logical narrative — and then you follow these assumptions through to the narrative endpoint. But the assumptions are not arbitrary. Indeed, I would argue that they are key to the whole model and to what it conveys.
Key observation. Constructing mathematical models does not mean that they are not narratives based on a POV determined by the assumptions.
Think of this like a film script. The assumptions give the story a narrative structure. Thus they determine whether the model is Sraffian or Marxist or marginalist, in the case of economics, and whether the film is a horror, a comedy or a romance, in the case of a film script. The different narrative structures — or genres, if you like — convey different things to the people who use them.
Fixing the Economists
The Sraffian Versus the Marginalist Worldview: A Strong Case For Academic Pluralism
Philip Pilkington
Models have to be tested, to see if their predictions agree with observed data.
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