In our article, Negligence and Insufficient Activity, we proposed that tort scholarship has overlooked the risk that injurers will behave strategically in setting their activity levels. Whereas the standard literature has predicted that injurers who are subject to a negligence regime will often invest efficiently in care but choose excessive activity levels, we showed that they may do exactly the opposite: injurers may deliberately restrict their activity to avoid investments in socially desirable precaution. After reviewing the conditions that may give rise to the risk of insufficient activity, we examined the ways in which the legal system can minimize the costs of such behavior. We hoped that our article would spark new interest in the interplay between tort liability and levels of care and activity. We are fortunate that three prominent tort scholars have already provided important insights on both our positive argument and our policy recommendations.

These responses vary in their assessments of our contribution to legal scholarship. While some find that our article addresses an "interesting omission in tort law scholarship" and highlights a "missing paradigm" that is "central to negligence doctrine," others consider it a "novel brick on a road that runs in the wrong direction." Nevertheless, and although the responses focus on different parts of the article, they share several important objections to our analysis.

A response to David Gilo & Ehud Guttel, Negligence and Insufficient Activity: The Missing Paradigm in Torts, 108 Mich L. Rev. 277 (2009).

In Negligence and Insufficient Activity: The Missing Paradigm in Torts, David Gilo and Ehud Guttel argue that negligence law encourages inefficiently high and low levels of activity because negligence law ordinarily does not take activity levels into account. They suggest that the law should impose liability for failing to take safety precautions-even where precautions would not be cost-justified-whenever the threat of this liability negates the incentive for an actor to choose an insufficient level of activity. Until now, the literature on the interaction between liability standards and activity levels has failed to recognize the possibility of inefficiently insufficient activity. I commend Gilo and Guttel for both their insight and their explication of it.

A response to David Gilo & Ehud Guttel, Negligence and Insufficient Activity: The Missing Paradigm in Torts, 108 Mich L. Rev. 277 (2009).

Professors David Gilo and Ehud Guttel have written an important article on the tendency of the negligence rule to produce inefficiently low activity levels. In Negligence and Insufficient Activity: The Missing Paradigm in Torts, the authors claim insufficient activity to be the "missing paradigm" in tort theory. Although I agree with Gilo and Guttel that this missing paradigm is central to negligence doctrine, I disagree with them about how insufficient activity levels arise.

A response to David Gilo & Ehud Guttel, Negligence and Insufficient Activity: The Missing Paradigm in Torts, 108 Mich. L. Rev. 277 (2009).

Within the law and economics field, there often surfaces a near hypnotic attraction to the Hand formula as the one and only tool that drives tort law toward economic efficiency. Hand's intuition was, of course, that the test for efficiency requires a balancing of three variables. The burden of taking particular precautions is compared to the expected loss from some activity, which in turn consists of the likelihood of some particular harm multiplied by its anticipated severity. Liability attaches only where the burden of precautions is lower than the anticipated accident costs. By forcing cost-effective precautions and no others on potential tortfeasors, so the story goes, tort law weeds out desirable from undesirable conduct.