In the copyright policy debate, proponents of strong copyright protection tend to be dismissive of the quality of freely available content. In response to counter-examples such as open access scholarly publications and advertising-supported business models (e.g., newspaper websites and the over-the-air television broadcasts viewed by 50 million Americans), the strong copyright proponents center their attack on amateur content. In this narrative, YouTube is for cat videos and Wikipedia is a wildly unreliable source of information.Recent studies, however, indicate that the volunteer-written and -edited Wikipedia is no less reliable than professionally edited encyclopedias such as the Encyclopedia Britannica. Moreover, Wikipedia has far broader coverage. Britannica, which discontinued its print edition in 2012 and now appears only online, contains 120,000 articles, all in English. Wikipedia, by contrast, has 4.3 million articles in English and a total of 22 million articles in 285 languages. Wikipedia attracts more than 470 million unique visitors a month who view over 19 billion pages. According to Alexa, it is the sixth most visited website in the world.Wikipedia, therefore, is a shining example of valuable content created by non-professionals. Is there a way to measure the economic value of this content? Because Wikipedia is created by volunteers, is administered by a non-profit foundation, and is distributed for free, the normal means of measuring value — such as revenue, market capitalization, and book value — do not directly apply. Nonetheless, there are a variety of methods for estimating its value in terms of its market value, its replacement cost, and the value it creates for its users. These methods suggest a valuation in the tens of billions of dollars, a one-time replacement cost of $6.6 billion with an annual updating cost of $630 million, and consumer benefit in the hundreds of billions of dollars
