Today marks the 20^th anniversary of Wikipedia’s website going live. The online, collaboratively sourced encyclopedia is one of the internet’s biggest success stories, but one that, on the face of it, conventional economic analysis would suggest was the least plausible.

The free, volunteer-edited site today hosts 55 million articles in 300 languages, including 6.2 million individual content pages in English that have been subject to almost 100 million edits. The Wikipedia page about Wikipedia itself cites articles claiming it is the 13^th most popular site on the internet, with 1.7 billion unique visitors and 20 billion page views per month.

Some academics remain snooty about an encyclopedia that can be “edited by anyone,” but Wikipedia is often a go-to website for even established researchers looking for quick overview of conventional wisdom or to double-check a fact cited elsewhere. The site has been adopted by companies such as Amazon and Apple to answer factual questions in voice assistants and smart speakers, and by social media companies such as Facebook to provide information links on posts.

There is good reason for this. A 2005 Nature study found that Wikipedia had decent accuracy compared to the expert-written Encyclopedia Britannica. Why? Aggregating information from a wide and diverse editor and reader base helps quickly correct obvious errors, especially on contentious and highly read topics. The articles that are most read then, over time, tend to be more accurate. Embedded within Wikipedia’s model then is a market-style feedback mechanism that ensures resources head to improve product quality where demand is highest. And, of course, because it utilizes new, rapid internet technologies, this collaboratively sourced website can update much more quickly than the book-bound encyclopedias of yesteryear.

In a world of filter bubbles and media segregation, Wikipedia has also proven somewhat of a mediating resource. Analysis has found that a weak version of Linus’ Law holds for Wikipedia—that “Given enough eyeballs, all bugs are shallow.” On articles with plentiful contributors, such as political pages, the large number of editors combined with Wikipedia’s own evolving protocols helps achieve a high degree of neutrality.

This is an underappreciated success. Public debate focuses on the idea of internet gatekeepers “censoring” free speech. Wikipedia has largely avoided that accusation to date, despite being a highly read source with explicit safeguards to try to eliminate fake news and ill-sourced opinion. True, errors or slant are harder to police on less well-read pages. Wikipedia’s founder Jimmy Wales acknowledges that on certain niche topics, only those are who strong fans of the subject will tend to contribute, meaning the sentiment of articles will be biased. But in all Wikipedia is well-trusted and widely believed to be doing a reasonably decent job, especially compared to the media. Some research even posits that engaging in Wikipedia edits causes contributors on political topics to become less slanted over time. Imagine!

Of course, such an open model is made possible by Section 230’s intermediary liability protections. As a nonprofit enterprise, the Wikimedia Foundation cannot afford to litigate the decisions of its volunteer editors. Section 230 allows it to both avoid liability for user errors and rectify errors without provoking litigation from those unhappy with the changes. While discussions of the law often focus on the judgments of ‘Big Tech’ moderators, it’s important to remember it safeguards the ongoing editorial judgment of Wikipedia’s hivemind.

As a non-profit, Wikipedia is part of the rich tapestry of organizations that arise in a free economy. Often public debate overly focuses on “the market” versus “the government.” Wikipedia’s success as a free content, non-profit institution highlights how within free economic systems intermedia organizations arise that can develop safeguards and standards that achieve the desired ends willed on by people calling for heavy-handed government regulation, while obviating the need for that path which crushes new innovation.

Indeed, the site should be of particular interest to libertarians. Jimmy Wales is on record at Cato as highlighting that the inspiration behind it lay with his reading of Friedrich Hayek’s “The Use of Knowledge In Society.” That famous essay explained a key reason why central planning couldn’t match the efficiency of an open market. The market order is dictated by prices, which themselves reflect a host of locally embedded information that no single planner could ever comprehend or collect. Wales took the message to heart in regards to knowledge, thinking he could build something that could harness that localized, dispersed, and niche knowledge among individuals to produce a resource as globally comprehensive as possible.

Wikipedia is a useful case-study for economists on certain other policy issues.

First, its existence shows how services with public good-like characteristics can be provided in a free economy. Knowledge is something that is non-rivalrous (me knowing something doesn’t “use it up” and so prevent you from knowing it) and non-excludable (you can try to raise barriers to its acquisition but it can still spread relatively freely). Introductory economics textbooks would say these characteristics mean such a good or service would be underprovided in a free economy, requiring some state subsidies or provision. Indeed, some Wikipedia employees have been known to joke “Thank God our little enterprise works in practice, because it could never work in theory”.

Yet it turns out donors worldwide are willing to fund the knowledge venture because they find it useful or buy into the vision, while enough editors volunteer to participate because they find satisfaction and usefulness themselves from the pastime. Mastering Wikipedia’s rules and guidelines make this a bit like Terence Kealey’s “contribution good” idea.

Second, the website reminds us that network effects, other things given, enhance consumer welfare, rather than diminish it. In the Big Tech antitrust debates it’s common to read that competition is inherently stifled in social media or the search engine sectors because users find services more useful when large numbers of other people are using them. This is said to constitute a major “barrier to entry” for competitors. But from the consumers’ perspective, it’s good that certain companies have high usership rates, as this improves the quality of the product.

In the case of Wikipedia, it should be obvious that the readers benefit from large numbers identifying errors and removing biases. Yet nobody says “Wikipedia is unfairly monopolizing the online encyclopedia market,” because we recognize those benefits arise from an open, competitive process. So while there might be other anti-competitive conduct charges against Big Tech companies, the existence of “network effects” should be separated out from other issues and not talked about as if they are a “bad.”

Finally, Wikipedia is a great example of how internet-based products have enhanced human welfare in ways not picked up in conventional GDP statistics. The decline in the purchase of physical encyclopedias would show up as a decline in measured market activity. But because of innovations such as Wikipedia, we now have access to more information than they provided at zero out-of-pocket cost. Research from two years ago estimated U.S. consumers valued Wikipedia then at $150 per year. That’s some consumer surplus. For context, the cost of Encyclopedia Britannica’s 32-volume, five-yard-long set in 2012 was $1,400.

Sure, one can quibble that the way Wikipedia operates entrenches consensus positions and treats certain controversial ideas harshly. One can find examples of mistakes on the site, or bias or slant. But the counterfactual is the imperfect world we live in, just without Wikipedia. Human beings themselves exhibit biases every day. At least in-built into the editorial process is a means of correction. Even the Wikipedia page about Wikipedia is pretty critical!

Wikipedia itself will have to evolve as more internet-activity moves away from the desktop or laptop onto smart technologies. But for now, we should see sites such as Wikipedia as a testament to the open, collaborative opportunities a free economy allows.