AI reviewed · sources pending. Book associations have not been verified.
Nonlinear relationship
ConceptA nonlinear relationship does not follow a single straight-line rule across its domain.
Explanation or usage
The response to a change can depend on the starting point. A slope estimated in one region may differ elsewhere. Nonlinearity does not by itself identify an optimum or show which policy is best.
Common misunderstandings
A change must have the same effect regardless of the starting point.
In How Not to Be Wrong
General context reviewed · book attribution and sources pending
A useful application is to test whether moving in one direction always improves an outcome; the answer may change across starting points.