Authors:
  • [The notion of equilibrium] is a notion which can be employed usefully in varying degrees of looseness. It is an absolutely indispensable part of the toolbag of the economist and one which he can often contribute usefully to other sciences which are occasionally apt to get lost in the trackless exfoliations of purely dynamic systems.

    "The Skills of the Economist". Book by Kenneth Ewart Boulding, p. 14, 1958.