Negligence law seldom accounts for a person’s idiosyncrasies. The objective standard of care simply demands that people take reasonable care under the circumstances. One’s greater risk profile or ignorance of what the duty of care requires does not matter. A defendant breaches his duty of care when he fails to take reasonable care—nothing more and nothing less.Not so under personalized standards of care. In their new book, Personalized Law: Different Rules for Different People, Professors Omri Ben-Shahar and Ariel Porat imagine a world where legal systems can create standards of care that are tailored to each person’s risk profile, allowing parties to take optimal precautions and reach optimal activity levels. Ben-Shahar and Porat provide numerous ways in which each person can learn about his or her own standard of care and in which the legal system can learn about each person’s standard of care. Their proposals are exciting precisely because they challenge the old negligence law’s assumption that determining each person’s unique standard of care is not feasible. In this Essay, I want to highlight the best path forward for implementing a system of personalized negligence law. In Part I, I recount Ben-Shahar and Porat’s shift away from the objective standard of care toward personalized standards of care. In Part II, I argue that relying on individuals to know their respective standards of care based on the fact that they know themselves is a mistake. People are relatively unreliable when it comes to knowing particular facts about themselves and knowing how those facts correlate with personalized standards of care. Part III will then examine Ben-Shahar and Porat’s proposed avenues for implementing a system of personalized negligence law. Methods of informing people of those standards of care, I show, create a tradeoff between ex ante knowledge of one’s standard of care and the degree of applicability of that standard of care. In Part IV, I propose resolving this dilemma by equipping people with feedback mechanisms—ways of measuring and easily correcting their activities—to help overcome these limitations and implement personalized negligence law. With this framework of personalized negligence law in mind, Part V explores three normative implications of personalized negligence law
