By Lisa Staadegaard
Pierson defines path dependence as "referring to social processes that exhibit positive feedback and thus generate branching patterns of historical development”. From this definition we can derive that Pierson uses path dependency and positive feedback interchangeably. Here positive feedback is defined as a process that generates increasing returns, its inflexible, unpredictable, non ergodic and suffers from potential path inefficiency. However, are these concepts always the same?
The concept of positive feedback mechanisms is not only used in political science. It is especially popular in economics but can even be used to explain behaviour and biological processes. An example of this is given in a paper by Baker, where he claims that addiction is an instated positive feedback loop. Stating that appetitive drug actions increase appetitive stimuli resulting in an increase in drug use. This example perfectly fits the above given criteria for positive feedback, however can we call this a path dependent process?
This really depends on the definition used, if we look at the narrower definition proposed by Margaret Levi, path dependency is supposed to involve countries. Then, we could easily argue that the addiction example is not a path dependent process.
Path dependency in social sciences is used to describe a sequence of events, and should point out the importance of historical processes. In many other sciences we can see a similar pattern where A causes B which then leads to ‘increasing returns’, as portrayed by the drug example. However these examples often do not include such a heavy reliance on history, and are often not as irreversible as processes in politics or economics. Therefore the terms path dependence and positive feedback processes may be used interchangeably in political science, but cannot be used interchangeably in many other sciences.