Читать книгу Security Engineering - Ross Anderson - Страница 83

Some interesting empirical work has been done on how people manage their exposure to risk. John Adams studied mandatory seat belt laws, and established that they don't actually save lives: they just transfer casualties from vehicle occupants to pedestrians and cyclists [20]. Seat belts make drivers feel safer, so they drive faster in order to bring their perceived risk back up to its previous level. He calls this a risk thermostat and the model is borne out in other applications too [19]. The lesson is that testing needs to have ecological validity: you need to evaluate the effect of a proposed intervention in as realistic a setting as possible.