How I Work
Krugman's short essay about his own methodology — the four "Krugman rules" for doing serious work in a fuzzy field.
Listen to the Gentiles (take seriously ideas outside your discipline), question the question, dare to be silly with your models, simplify aggressively.
The piece is framed around economic theory but reads as a manifesto for how to think well in any field where you cannot run controlled experiments — which is most of product direction.
Krugman writes with unusual clarity about the relationship between simplicity and rigour: the point of a simple model is not that it is true but that it is honest about what it claims.
Short, unpolished, closer to a talk than a paper, and more useful for it.
Central argument
Krugman argues that productive work in economics — and by extension any field resistant to controlled experimentation — requires four disciplined habits: taking seriously ideas from outside your field ('listen to the Gentiles'), questioning whether the stated problem is actually the right problem, tolerating the apparent absurdity of deliberately simplified models, and aggressively stripping away complexity until only the essential mechanism remains. His central thesis is that a simple model's value lies not in its descriptive accuracy but in its intellectual honesty: it makes explicit what it claims and what it ignores, which is more rigorous than a complex account that hides its assumptions. The essay is a defence of toy models as a thinking tool, not a shortcut.
Critique
Krugman's rules are drawn almost entirely from his own experience as a theorist working with formal mathematical models, which means the framework quietly assumes that your discipline has enough structural regularity to model at all. The advice to 'simplify aggressively' can become a licence to exclude the messy social and institutional variables that turn out to be causally decisive — a tension Krugman acknowledges nowhere in the essay. A thoughtful reader might also note that 'dare to be silly' is easier counsel for a tenured economist with established credibility than for a junior researcher or practitioner whose professional standing depends on not being dismissed.
Why it matters for product
The injunction to question the question is directly applicable to product discovery: teams routinely over-invest in solving a well-specified problem without asking whether the specification itself reflects the real constraint, which is how roadmaps accumulate work that is executed competently but changes nothing. Krugman's point about simple models being honest about their claims maps onto a recurring failure in product metrics design — dashboards that aggregate too many variables produce the illusion of understanding while obscuring the one mechanism that actually drives the outcome a team cares about. Listening to the Gentiles has a structural implication for team design: if the people closest to the problem share a single professional formation, the discipline's blind spots become the product's blind spots.