Breach of Duty

- whether the act imposed an unreasonable risk on others in violation of the Hand Formula
- whether the parties to the loss were in a contractual relationship or market Rodi Yachts v National Marine
- whether transaction costs allow the parties to bargain as per the Coase Theorem; see Calabresi corollary
-whether high information costs make custom the best approximation to reasonable care, as in malpractice
- whether the act violated a statute or judge-made rule, implying per se negligence
- whether information-forcing rationales support a res ipsa presumption of negligence