Equilibrium is probably the principal focus of most areas of economic analy
sis. However, the policy maker is often interested not only in the equilibr
ium predictions arising from an economic model, but also in the path taken
by policy variables as they move towards that equilibrium. It is therefore
likely that integration into a dynamic framework will frequently enhance th
e usefulness of an economic model. Recent developments in computer software
mean that system dynamics offers a readily accessible methodology for maki
ng this principle operational. The approach is illustrated using an example
from the British National Health Service, in which a traditional economic
model of supply and demand is deployed within a system dynamics model. (C)
2002 Elsevier Science B.V. All rights reserved.