341Complex Economic Systems and Sustainability
7.2.1 Forrester’s Views
The challenge of formulating quantitative, dynamic models of complex ESs
(CESs) was recognized over 56 years ago by economist/mathematician Jay
W. Forrester (2003) at the Massachusetts Institute of Technology. In 1956,
Forrester commented on the factors governing the time-dependent interplay
of money, materials, and information ow in ESs and industrial organiza-
tions. The rst point he made was that CESs contain causal feedback loops.
He wrote: “The ows of money, materials, and information feed one another
around closed re-entering paths.” He went on to state that such systems
often develop bounded oscillations (limit cycles), a well-known property ...