In defence of the linear model: An essay

This essay discusses the strength and weaknesses of the so-called linear model (LM) of innovation. It is a reaction to the habit of criticising it as over simplistic, mechanistic, or simply blatantly wrong. We argue that, while some criticisms are of course well grounded, many others are instead based on loose interpretations and unwarranted assumptions. In order to separate the wheat from the chaff, this essay first presents a comprehensive description of the linear model and differentiates it from the caricature many refer to. Second, we discuss the main criticisms put forward and argue that many of them are not at all destructive, but can be easily accepted within a refined version of the LM. Third, we discuss the policy implications often derived (or said to derive) from the LM to argue that the LM itself is distinctively policy-neutral. Other assumptions have to be added to justify alternative policy implications. (C) 2009 Elsevier B.V. All rights reserved.