The phrase "the shrinking public domain" is a figure of speech (at least it should be understood as such).

Protecting something with IP does not detract from the public domain because whatever is in the public domain cannot be covered by copyrights, patents, trademarks in the first place. Thus nothing is deprived from the public domain, nothing is taken out of it.

"The shrinking public domain" *may* apply to retro-property right term extensions however, as the grant of a property right came with it the condition that the public domain would received the property at a fixed time. However, I'm still dubious of the phrase here.

The public domain is important. It provides a buffer to all forms of IPRs. However, I would not see the two as opposites, or mutually exclusive. In some ways, IPRs can be seen to enhance the public domain; by giving to it artistic works, information and innovations in a more refined state than would exist without IPRs.

The measure I would say I find most irksome is the length of time it takes work to enter the public domain. It isn't just that nothing created during any of our lifetimes is likely to enter the public domain during our lifetimes -- which itself is unprecedented in the history of copyright -- but also that nothing will enter the public domain until well after we are dead. Barring any change in direction from lawmakers here or abroad, we are looking at a public domain that has been stopped dead in its tracks for the foreseeable future. It's not "shrinking," but it's also not growing. All the established players, which now amount to a handful of multinational corporations that collectively control a huge portion of 20th Century cultural output, had the advantage of building on a robust public domain. Disney, for example, built a large measure of its business on the back of work that appeared in the mid-to-late 19th Century and came into the public domain in a timely fashion. And Disney did it spectacularly well. But now no one has that opportunity, thanks in no small part to the lobbying of Disney itself, and the willingness of Congress to sell our cultural heritage to the highest bidder. This is what has led many to the inevitable conclusion that copyright has been distorted beyond all standard of reasonableness and transformed into nothing more than a protectionist racket.

The universe is expanding or contracting - well it depends on dark matter and other things that have not been taken into account or are unknown (space dimensionality, new particles etc). Talking about future of universe is still more a sf than science (that cannot even physically explain a nature of human consciousness).
I think that public domain it is easy to explain. It is all knowledge and traditions, expression forms (arts) if automatically granted copyrights has expired or never has been assigned (old things) and applied knowledge covered by patents that has been dropped or expired. Public domain is not shrinking but is much more dispersed in society covered be more visible commercial - IP (however if the protection terms are extended then public domain suffers or grow slower).

"How does one measure such a thing?" - it is everything that is not assigned to owner by law.

"Do we count as "public domain" things that can never be claimed as IP, such as facts or ideas?" - yes it is in fact a freedom of speech you cannot protect facts or mental acts! However collected data describing facts are protected for example in Europe (databases protection). Ideas implemented in physical form may be protected by patents. Copyrights in fact covers unique (what is especially important because of freedom of speech) composition and expression of abstract ideas.

There is also a semi-public domain where works protected by copyright are licensed in some scope for free like FOSS, works under Creative Commons (see Wikipedia, PLoS, Jamendo, Project Gutenberg etc.). These enterprises usually mixes public domain and freely accessible IP. These enterprises develop more culture not commerce.

There border between those "world" is in fact a matter of commercialization of culture and effort protection. If you do something you should have opportunity to be rewarded unless you do not expect that. Reward encourages you to stronger further work. However, too strong (and long) protection gives too much reward and discourage you to further work. What is more, too strong protection slow down the grow of public domain so the others (culture) are developing slower or less. Less developed culture will develop less amount of IP in the future. And you receive negative feedback. The matter is a social deal and proper system tuning to encourage not discourage. It is similar in effect to Laffer curve in taxes.
The worst thing that may happen is to loose regulations for what is protected and what is not if the IP growth is dropping. Then you inflate negative feedback you at the cost of temporary hasten in the IP amount. And then boom... death row. Positive feedback you receive by putting more money in education and culture.
From this point of view FOSS and Creativity Commons are very positive things. The problem with the public domain is that it is fragmented now. Some enterprises like Wikipedia tries to organize that but is this a lot to do in making all culture available for all people.

To extend my thoughts I have to add that the difference between culture and commerce is like between global and local optimization. Culture activates and develop whole society even the poorest giving better changes to find and develop new talents. However commerce (of the proper IP strong) optimizes locally encouraging boost in developing the most efficient participants in system. The matter is to not to sacrifice culture so public domain for developing commerce. Then the system will not self regulate and stuck. But life is going further and soon such system will be just not optimal.

Why the obession with measuring it, and what use would that have?

First, I would measure what is not in the public domain, as that represents a special class of speech that is abridged. That is, someone has been given a (temporary) governement-granted monopoly on that particular speech. Then I would measure the length of that abridgement.

The extension of that government granted monopoly represents a limitation of freedom, and in most moral systems, limitations of freedom should be minimized.

Mr E, you are equating the public domain with all that can possibly fall within it.

There is a definition for the public domain, but evidently that definition is expanding further than than the public domain itself....

Noel, if e_f is operating on a flawed definition of the public domain, then please state what you think the proper definition should be. Your vague statements help no one.

Lewis, I agree with Webster's definition of the public domain: the realm embracing property rights that belong to the community at large, are unprotected by copyright or patent, and are subject to appropriation by anyone.

Under Mr. E's definiton of the public domain, *everything* that can possibly fall in the public domain *should be * or *is* in the public domain. I disagree with this because it basicially repeals all copyrights and patents by implying that they've somehow reached into the public domain and took something away from it (which is not possible, if something is public domain, its neither copyrightable nor patentable.

Lewis, I've done some writing on the public domain. see:

http://weblog.ipcentral.info/archives/2006/09/the_public_doma.html

Then the difference is merely syntactic quibbling. Whether you view, as e_f does, that IP protections "take away" from the default public domain commons or whether you believe that a work does not enter the public domain until after its protections expire makes little difference. The effect is still the same. IP protections slow the expansion of the commons at the same time they ensure (via profit incentives) an ongoing supply of works entering the commons (via expiration of IPRs).

Syntactic quibbling? I gave you a definition, and explained how it differed from Mr. E's, and told you how that affects policy discourse. Some people are hard to please...

Your concept of the commons is interesting. Imagine this: if nothing is protected by IP, then how does the commons grow or expand. What is put into it?

"Syntactic quibbling? I gave you a definition, and explained how it differed from Mr. E's, and told you how that affects policy discourse."

No, because you make some assumptions that lead you to incorrect conclusions about my position (I'll cease putting words in Mr. E's mouth and speak for myself). I'll attempt to untangle it:

"I disagree with this because it basicially repeals all copyrights and patents by implying that they've somehow reached into the public domain and took something away from it (which is not possible, if something is public domain, its neither copyrightable nor patentable."

But under Mr. E's definition (as I understand it) of "public domain" (which I assume is my definition of the commons), something in it *is* copyrightable or patentable (to a limited extent, by government intervention), so the implication they are not is false.

"Imagine this: if nothing is protected by IP, then how does the commons grow or expand. What is put into it?"

I'm confused how my statements led to this question. IP provides financial incentives for new works, which eventually fall into the public domain. Nothing I said contradicts that.

***But under Mr. E's definition of "public domain" (which I assume is my definition of the commons), something in it *is* copyrightable or patentable (to a limited extent, by government intervention), so the implication they are not is false.***

Here is where we differ.

I'll post something end of next week (totally crunched now with time) about the public domain. Feel free to email me or point me to some resources you think are important on the topic.

Another quick note Lewis. The public domain and the commons may not be the same thing (although if you're an IP critic, they are functionally the same). The public domain is a legal reference, the commons, well, I think the commons is a less formal term. The implication is that you may have to distiniquish them when talking about IP.

"First, I would measure what is not in the public domain, as that represents a special class of speech that is abridged."

I didn't draw the distinction between the 'commons' and the public domain because that wasn't what I was interested. I will grant you that a distinction exists.

"Second, I would measure the rate at which things enter the public domain, that is the velocity of IP.

I would maintain that having a significant, stable flow into the public domain would be an engine of economic growth.

Has the flow been significant and stable, or is it merely a trickle?"

SO II would measure the rate of IP flow, as part of a dynamic system, not as a static entity.

"Mr E, you are equating the public domain with all that can possibly fall within it."

Noel, how on Earth did you come to that conclusion from what I said? It was not my intent to define the public domain, or the commons.

What I suggested was a different way to measure it.

What concerns me more than the absolute size of something (a static measurement) is the rate of flow in a (dynamic) system.