I've recently been attempting to discuss commons and the tragedy of the commons with regards to the Internet with Luca De Biase.
To summarize/recap the conversation, he posted a response in Edge, I questioned the notion of the Internet being a commons that disproved the idea of the tragedy of the commons and he's replied further. He also brought up this paper on the concept of a knowledge commons.
In the original post, the root of our disagreement is his statement "But the Internet has grown to become the biggest commons of knowledge in history." before going on to explain that there isn't a tragedy of the commons awaiting the Internet as a fate. To an economist the idea of a tragedy of the commons refers to a specific type of commons and Luca De Biase's commentary to that effect appears to be a commentary more on why the Internet is not and should not be considered a commons.
It appears that once we've come to terms (English isn't his first language, so much should be excused based on that), Luca De Biase and I will agree on most points. As defined in the reference knowledge commons paper, knowledge is a "Public Good" in the economic sense. Knowledge is not rivalrous (we can both use the same knowledge without excluding others from it) and not subtractable (we can both use the same knowledge without damaging that use of that knowledge by someone else).
The confusion seems to result from the overloading of the term "commons". In English language economic terminology, a commons is by definition something that is rivalrous and subtractable. The "Tragedy of the commons" refers to the usage patterns of goods that are considered under common ownership (effectively no true ownership) vs. goods where someone in particular has an ownership interest to see them preserved. See The Concise Encyclopedia of Economics for a good summary if you are unfamiliar with the idea.
It is the nature of the "commons" thus described that leads to the "tragedy". A necessary prerequisite for a tragedy of the commons is that one person's use can negatively impact another person's use.
It seems obvious that because one person having knowledge or information doesn't prevent others from having that same knowledge or information, knowledge isn't a commons in the economic profession's sense of the word. Because knowledge isn't a commons in the sense of the word being used in the phrase "Tragedy of the Commons", it's nonsensical to state that existence and usefulness of shared knowledge somehow disproves the tragedy of the commons.
Happening to be one of those rare individuals who have a big background in both economics and in the Internet, having founded an Internet Service Provider (ISP) and worked in the e-commerce industry since before it really existed, I suppose I'm uniquely situated to criticize the analogy from both sides.
For you see, the Internet itself, the literal physical thing we call the Internet, consists of individual nodes of private property and contractual agreements. It's not "public" at all, in the sense that everyone owns it. Quite the opposite. It's a Catallaxy, a free marketplace where anyone can agree to connect to anyone else with their own private property. Where this breaks down is that in some locations (I'm looking at you, American cities) the government establishes monopolies around some specific methods of getting a connection to the Internet (see cable monopoly). Thankfully, there are generally decent alternative methods available to most private individuals. Where the Internet really shines is at the backbone/ISP level. Internet Bandwidth providers (people with contractual relationships to exchange network traffic with others) compete to offer different types of connections. ISPs make contractual agreements to carry Internet traffic for one another. At every connection point, contractual agreements are in place that govern the private use of the connection in both directions. Some of the business rules involved are enforced at a technological level, while others are simply enforced by cutting the connection if the other side isn't honoring them.
For you see, the reason why no one can "abuse" the internet, the reason it can not devolve into a "Tragedy of the Commons" is because of these private agreements and the availability of alternative competitors. Abuse, at it's simplest level on the Internet, is defined as doing something the owner of a network doesn't want you to do. At best, someone can only do bad things on their own network. If abuse spills out into someone else's network, then the offender is ultimately cut off by the nodes they connect to at the network level. This ability exists because there are specific owners of these networks who are responsible for their care and maintenance and responsible for ensuring they continue to serve the purposes of their owners and customers.
You can name distributed accessible knowledge a "knowledge commons". Just realize the Internet is a distinct thing. Your web browser and someone else's web server are things that use the Internet to connect to each other, they aren't the Internet. i.e. your car isn't a private highway.
Thankfully, there is much we agree on. Knowledge isn't a commons and thus doesn't need a tragedy of the commons solution. That's a truism much easier to understand once you understand the characteristics of an economics commons and how they don't apply to knowledge and information. This also makes it easy to see that most intellectual property laws, the ones that try to turn knowledge or information into a form of property, don't make a lot of sense. Copyright must stand under another justification than some misguided idea that people will "use up" too much information, thus denying that information to others. Just stating that idea shows how nonsensical it is. There are good reasons the USSC ruled you can't copy-write collections of facts.
So primarily, what we agree on is that while there are conflict among people around knowledge sharing rules and laws, the tragedy of the commons doesn't apply and has few lessons for that discussion. I think creating the term "knowledge commons" only serves to advance the misunderstanding that knowledge might be a commons, but some special sort of commons, but I suppose that if the proponents can distinguish it well enough that those involved aren't confused, it may work out for them. Personally, I'd just state that the rules of a commons don't apply to knowledge because it doesn't have the properties of a "commons", historically defined. That seems sufficient to dispose with the tragedy of the commons argument and get into the real issues of how to deal with a world where almost anyone can access a virtually costless reproduction of any information being made available for copying.
But don't forget, when you talk about global distributed information, the "distribution" portion of that is a triumph of spontaneous order created by individuals and groups acting in their own best interests. There is no International Internet Committee that establishes how each network will be allowed to connect to another and what types of network traffic they will be allowed to pass. To paraphrase Adam Smith, it is not from the benevolence of the bandwidth seller that we expect our information, but from their regard to their own interest.