One of my favorite mental models for an entire industry (quant finance): "'P' Versus 'Q': Differences and Commonalities between the Two Areas of Quantitative F

One of my favorite mental models for an entire industry (quant finance): "'P' Versus 'Q': Differences and Commonalities between the Two Areas of Quantitative Finance" https://papers.ssrn.com/sol3/papers.cfm?abstract_id=1717163 https://papers.ssrn.com/sol3/papers.cfm?abstract_id=1717163 Summary: Quantitative Finance comes down to two tasks: "model the future" (P world) or "extrapolate the present" (Q world).