People may adjust their behaviour in response to perceived changes in risk, partly offsetting the benefit of safety measures.
Peltzman's 1975 analysis argued that behavioural offset could erase much of the benefit of auto-safety regulation. Subsequent studies disputed both the size of the offset and, in some settings, whether it exists at all.
In practice
- Treat as contested: the claim is that safety measures are partly offset by riskier behaviour, and the size of any offset is disputed.
- A team given an automatic rollback deploys more carelessly, and the total incident count does not fall as far as the tooling predicted.
- Possible explanations
- The explanation is that people choose a level of risk rather than a level of care, so a measure that makes an activity safer lowers its perceived cost and some of the gain is taken back as speed or inattention.
- In its favour
- Partial offsetting is documented in several settings, including anti-lock brakes and protective equipment in sport, and the mechanism follows from ordinary behaviour under changed prices.
- Against it
- Both the magnitude of the offset and, in some settings, its existence are disputed, and mandatory seat belts and similar measures have produced large net reductions in deaths, so the offset is partial rather than complete.
- Standing
- Absorbs risk compensation; both the magnitude of the offset and, in some settings, its existence are disputed.
- Subject
- Psychology & Behavior
- Essay
- A century and a half of measuring the mind