Campbell's law
Topic: Schools of Economic Thought and Economic Laws · NCERT: Beyond NCERT
Meaning
Campbell's law, from the psychologist Donald Campbell (1976), says this: the more a number is used to make social decisions, the more people bend it. The number is corrupted, and it also distorts the activity it was meant to measure. People start working to move the number instead of improving the real thing behind it. It is a warning for any target-driven scheme or ranking in education, health or governance.
Example
Suppose schools are judged only by board-exam pass rates. Teachers then "teach to the test", drilling likely questions instead of building real understanding. Pass rates rise, but learning may not.
Don't confuse with
- Goodhart's law: Charles Goodhart (1975) stated it about the Bank of England's money-supply targets: "When a measure becomes a target, it ceases to be a good measure." Campbell's law is the social-science version, and it adds that the process being measured is also distorted.
Related concepts
- Baumol's cost disease
- Jevons paradox
- Goodhart's law
- Parkinson's law
- Broken window fallacy
- Lump of labour fallacy