Wbat do you know about Path Dependency?

Hmmm, trying to think of a good one. Never heard the term before, but it certainly describes a hell of a lot of biology...

I'm not really sure the DVD issue is related to path dependency in your 2nd example but that's neither here nor there I suppose.

The basic principle is pretty straight forward.

A leads to B which leads to C and then on to D, E and F...

You can apply that to biology (as patio mentioned), technology, sociology, etc.. It's just a matter of tracing how we got to where we are. (PBS used to have a great show called "Connections" that was really nothing but explanations of different cases of path dependency.)

Umm.. human blood types are a form of path dependency. Say your paternal Grandmother was a O Neg, your Paternal Grandfather was AB, your Maternal Grandmather was O Pos and your Maternal Grandfather was AB.

In both cases your grandmothers would have contributed an O allele to each of your parents. If both of your parents inherited the A allele from their fathers then both of your parents would have type A blood.

Because of that you (and any siblings born from the same parents) could never be blood type "B" or "AB". Your blood type is tied to your parents so you can only be a type O or a type A yourself.

And if you inherited the A allele from both of your parents you can't pass on the O allele to any children you might have. You can only pass on an A allele.

The path to you is dependent on what came before you and the path after you is dependent on what you pass on.

BTW - the famous quote goes "Its not first to market, its first to scale", once you have market share you also have market inertia on your side.

billy falcon-Up until this evening, I knew NOTHING about path dependency. It is a fascinating subject, and I found an interesting article, which cites some of your examples:

http://www.huppi.com/kangaroo/Pathdependency.htm

I can't seem to do it on this keyboard, but on my old one, I could adjust the keyboard from QWERTY to Dvorak. You can buy stickers that you can place over the keys, or if you are handy, can remove and replace each individual key.

According to what I have read, the Dvorak keyboard places the keys by how often they are used. It is supposed to be much easier to learn to type on a Dvorak. If you already use QWERTY, I have read that it takes about a month to get used to the switchover.

Great link, Phoenix. Thanks. (I, too, had never heard of path dependency until tonight.)

Hmmm. I wonder, if you make the switch, if you still retain your ability to type on a qwerty board. I'd guess yes...

Yeah, I'd guess it would be like knowing more than one language. Might need to have a period of adjustment each time you go back and forth. ("How's this go again?")

Hmm. I was thinking of it in terms of musical instruments, but you've probably got the better analogy.

Musical instruments makes sense, actually. Muscle memory.

Hmmm. If I think of it in terms of a piano keyboard, it would actually be wickedly hard, because the keys are ordered.

A better example might be the diferrent woodwind instruments, which "overblow" at different intervals. And plenty of people are able to play many different woodwinds, so it prolly ain't too hard.


(wee thread hijack here)

(wee)

Interesting concept, though, billy falcon, thanks for bringing it up.

Just a (wee) question here. Is path dependency comparable to "chaining" in psychology? i.e. one stimulus elicits a response which elicits a stimulus, etc.

Path dependency
I assumed you were talking about the difference between state and path functions. With path functions, the happenings between one point/event and the next are relevant; with state functions only the two points/events are important. The simplest example I know of regards distances.

Say you want to get from San Francisco to New York. A state function of the distance you travelled would just tell you that you went X miles/kilometers as the crow flies. A path function would tell you exactly how far you went depending on what route you took: for instance, you would travel much farther if you made a stopover in Mexico City before going on to New York, as opposed to only travelling through the intervening states.

Or, if you were making a round trip, the state dependent function would say you travelled a total of 0 miles, whereas the path dependent function would give the actual distance logged.

Think of it as the odometer in a car. If you drive one mile forward, and then one mile in reverse, the odometer will NOT say you went zero miles.

So in reference to the Qwerty/Dvorak keyboards issue, the point is that by placing the most frequently used letters as close as possible to the "home" range (i.e. the places your fingers rest on the keyboard), the Dvorak keyboard minimizes the movements of your fingers. This allows you to type faster, and thereby reduces the amount of stress to the hands and wrists.

Hope that helps!

Hmmmm, I think the point is that we're stuck with the inefficient qwerty keyboard because the "path" doesn't let us move to a better one. The jump is not economically feasible, thus the configuration of future keyboards is dependent on earlier decisions.

patiodog,

You hit the qwerty key right on its eighteenth century head. It's as antiquated as anything could be and still be in use.

Isn't it ironic that querty is operating right alongside the most sophisticated electronic equipment?

Policy and Path Dependence
From QWERTY to Windows 95
Stan Leibowitz and Stephen E. Margolis

Excerpts:

The first explicit application of this concept to economics is credited to Brian Arthur, who warns of the danger of "lock-in by insignificant historical events." Paul Krugman captures the idea in a succinct definition of path dependence: "the powerful role of historical accident in determining the shape of the economy."


On the face of it, the arguments of the advocates of path dependence have tremendous appeal. After all, it is hard to deny that if the right accident occurred, such as a meltdown of a nuclear reactor, it might have considerable consequences. But the type of accident that is envisioned in the path dependence literature is not of that magnitude. Rather, it is of the insignificant kind: a head start, a quirky choice, a passing condition.


Furthermore, lock-in has a very specific meaning in path dependence literature. In some sense, of course, we are all locked in?-if only to eating, breathing, and remaining in our solar system. But that is not what lock-in means in the path dependence literature. In path dependence, getting "locked-in" means having to accept inferior standards or products, even though superior alternatives exist, even though it is known that superior alternatives exist, and even though the costs of switching are not high.


What is especially important is that for Arthur, Krugman, and other path dependence theorists, path dependence is no oddity: it is a likely phenomenon that can affect choices of technologies, networks, standards, industrial location, or almost any arrangement that might exhibit what economists call increasing returns to scale. And according to these authors, increasing returns, which is economist-speak for the idea that bigger is better when it comes to the production of goods and services, is a common phenomenon, one that is found in virtually all high-tech industries.


It is only a small step from there to sweeping policy prescriptions. In general discussions, path dependence arguments have been used to support active management of trade and every sort of industrial policy. Taking one specific case, path dependence arguments have been used to support antitrust actions against Microsoft. A white paper by Gary Reback and a group of coauthors, with assistance from Brian Arthur, uses path dependence arguments to claim that Microsoft's successes in the personal computer software market are due not to Microsoft's ability to provide consumers with handy solutions to their problems, but instead are caused by consumers' inabilities to escape from a path controlled by Microsoft. Reback, et al. chillingly portray the ominous end of that path: "It is difficult to imagine that in an open society such as this one, with multiple information sources, a single company could seize sufficient control of information transmission so as to constitute a threat to the underpinnings of a free society. But such a scenario is a realistic (and perhaps probable) outcome." Lock the doors, it might be Windows 95, come to enslave us.

http://www.cato.org/pubs/regulation/reg18n3d.html

Thing is, I can't really think of a sentence a whole lot faster than I can type it, so it doesn' worry me all that much. (Then again, maybe the speed at which I think while I type is conditioned by the speed at which I am able to type.)

Yah, Krugman's path dependence theory is interesting. I have a chapter on historic path dependence in my dissertation, as one of the factors explaining ethnic conflict in central europe. cumulative causalities that cannot be reverted.

Oh, interesting.

Does this mean that the dread dissertation has been dispatched? Finished finished finished?

If so, I'd love to read it.