Theory and Model Craft (ier-theory-model)

When to trigger

• The model "works" numerically but you cannot say which assumption is doing the work
• Existence/uniqueness of equilibrium is asserted rather than proved, or relies on a knife-edge condition
• A referee suspects the headline result is an artifact of a functional-form or parametric choice
• The comparative statics are stated but the sign of a key derivative is not signed cleanly
• You are unsure the model is general enough — does the result survive perturbing the convenient assumption?

Why theory is central at IER

IER tilts theory/structural, and for theory and structural papers the model is the contribution — so the bar is not "is the model plausible" but "is the result tight and general." A tight result names exactly which assumptions are load-bearing and shows the conclusion is not an accident of a convenient functional form. This is the difference an IER referee looks for between a paper that teaches a general lesson and one that re-derives a known fact under new notation.

What makes a result "tight" at IER