Path Dependence

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'''Path dependence''' exists when the outcome of a process depends on its past history, and is certainly a property of many [[Complex Adaptive System|complex adaptive systems]]. It occurs when taking one choice precludes another and influences the next. Apparently, [[Adaptive_System|adaptive systems]] are [[Context Dependence|context dependent]]. Repeated [[Context Dependence|context dependence]] can lead to path dependence if the context-dependent changes are permanent and durable. In this case the behavior in the current situation depends on the previous behaviors of the system during the history of existence, rather than simply on current conditions. Path dependence exists in a world of possibilities which depends on previous choices, if the kinds of doors we can go through depends on the kinds of doors we have opened before. Depending on the path of the system, the behavior, experience and outcomes may vary. 

Thus path-dependent behavior occurs generally in [[Adaptive_System|adaptive systems]], if microscopic perturbations, minor fluctuations and small differences in local conditions are amplified and reinforced to macroscopic differences, especially in systems with positive feedback. Strong path dependence can be found often in systems with strong positive [[Feedback|feedback]] and is related to the [[Butterfly Effect|butterfly effect]], [[Lever_Point|lever points]] and [[Frozen Accident|frozen accidents]]. 

Econmic examples are the QWERTY layout in typewriters which is still used in computer keyboards, or file line endings for different operating systems (originally CRLF in Windows, and in LF in Linux and CR in Mac).

Phenomenal [[Consciousness|consciousness]] and [[Subjectivity|subjective experience]] are path-dependent and vary strongly from person to person, because each person has a different history, has met different people during the past, and is adapted to a slighty different world.

Path dependence is quite similar to Murray Gell-Mann's [[Frozen_Accident|frozen accidents]] and John H. Holland's [[Lever_Point|lever points]], although both focus more on the beginning of the path than on the path itself.

== References and Links ==

* [http://en.wikipedia.org/wiki/Path_dependence Main Wikipedia Entry for Path Dependence]
* C2 Wiki [http://c2.com/cgi/wiki?PathDependence Entry for Path Dependence]

* Notebook entries for [http://cscs.umich.edu/~crshalizi/notebooks/qwerty.html QWERTY, Lock-In and Path Dependence]


[[Category:Basic Principles]]