The topic that I have attempted to explore is the usefulness of these — Arnold Tustin

"Feedback: It is the fundamental principle that underlies all self-regulating systems, not only machines but also the processes of life and the tides of human affairs."

"Methods by which engineers stabilise their mechanisms suggest analogous possibilities for stabilising economic systems."

"The analysis of engineering systems and the understanding of economic structure have advanced since then, and the time is now more ripe to bring these topics into a potentially fruitful marriage."

"Already well known to engineers all over the world as a pioneer in the development of automatic control, it may well turn out that Gordon Brown will make a still deeper mark on the engineering development of this century."

"He is transported to that curious world of decibels and negative frequencies where filter experts live."

"There are certain formal similarities between the problems of devising policies for economic stabilisation and those of designing automatic control systems. Methods have recently been developed by engineers for analysing the dynamic properties of quite complex models... [which] can also be used for the analysis of dynamic process models in economics... Professor Tustin’s book contains material of fundamental importance for all who are engaged in either theoretical or empirical studies of dynamic processes in economics. It throws new light on the possibilities and the difficulties of quantitative research in this field."