Economics. Supply and demand; marginal cost; utility curves; comparative advantage; resources and productivity – all these explanatory concepts fall into economics, a powerful framework to illuminate a host of problems and solutions. It is the best set of tools for thinking through how to manage a law department (See my post of March 3, 2006: economics with 16 references; Sept. 19, 2008: economic concepts with 43 references; and July 23, 2009: sub-disciplines within economics.).
Psychology also offers many insights into the lawyers and non-lawyers of a legal department. For example, it clarifies risk and return, incentives, timidity and aggressiveness. Eventually, psychology may be subsumed by neuropsychology (See my post of June 22, 2008: neuroscience with 32 references; July 21, 2006: psychology with 24 references; and April 22, 2009: psychology with 16 references and 9 metaposts.).
Sociology is the third discipline that especially helps us understand that particular group of people, the tribe of law departments. It brings to bear such important managerial concepts as peer pressure, hierarchy, turf, competition, rumors and trust (See my post of July 21, 2006: sociology with 14 references.).