Law and Equity: The Generator Analogy

Today I am working on materials for the remedies casebook that is edited by Emily Sherwin and me. (The book is Ames, Chafee, and Re on Remedies, third edition.) I included an analogy that readers of the blog might be interested in:

By the way, one of us illustrates the idea of law and equity as two systems like this. Imagine an entity that must have access to power, such as a hospital or a computer server facility. It won't want to run to generators all the time—the cost would be extraordinary, and the pollution. So the hospital or server facility quite sensibly uses power from the electric grid. But what happens when there is a disruption in the transmission of power to the hospital or server site? Should it simply "go dark"? No, again sensibly, it uses a backup generator system. Now one could ask, "Why not just ensure there are no failures in the transmission of power from the electric grid?" But it is more efficient to get the power grid to 99.9% reliability, and have a backup generator for the .1% of cases, than it is to try to make the power grid so perfect that it is 100% reliable. For law and equity these aren't the percentages, but the analogy is helpful in showing how two systems can work better than one, with one system providing the general rule and the other as a backup when there is a failure in system one.

If you want to explore further the idea of law and equity as distinct systems, good places to start are Henry E. Smith, "Fusing the Equitable Function in Private Law" in Private Law in the 21st Century 173 (Kit Barker, Karen Fairweather, and Ross Grantham eds., 2017); and Henry E. Smith, "Equity as Meta-Law," Yale L. J. (forthcoming).