With the Wikipedia blackout in the face of protests over SOPA/PIPA we here at Centives began to realize just how much Wikipedia is worth to us. This led us to wonder: how much is Wikipedia actually worth in dollar terms? Centives decided to find out. There are several ways to value a massive encyclopedia on the scale of the English version of Wikipedia and each method has its merits. Centives decided to estimate its value by examining how much it would cost an individual or a company to develop an encyclopedia that was similar to Wikipedia.

Research suggests that Wikipedia’s quality is comparable to that of the Encyclopædia Britannica. Science writers could produce articles of roughly similar quality and their services can be brought for around $1 per word*. Wikipedia was launched in 2001 and by the end of the year it contained 4.3 million words distributed across 16,000 articles. So, if somebody had wanted to create an encyclopedia that had the same depth as Wikipedia in 2001 they would have had to pay science writers $4.3 million.

Over the next few years Wikipedia grew at an astonishing rate:

By the end of 2009 Wikipedia contained 1.7 billion words across 3.1 million articles. A company wanting to create a database as comprehensive as Wikipedia would have to pay writers $1.7 billion to equal the feat. This means that between 2001 and 2009 Wikipedia’s value grew at an average rate of 147% per year. In contrast Apple’s Market Capitalization has grown by 59% per year over the same time period and Google’s Market Capitalization has grown by ‘just’ 32% per year since it went public.

Data for the number of words contained in Wikipedia is unavailable past January 2010. However it might be possible to predict the number of words within Wikipedia based on past trends. Since March 2006, Wikipedia has grown at a fairly steady monthly pace and in the 17 months between September 2008 and January 2010 the number of words within Wikipedia grew at a monthly rate of 2%. If we conservatively estimate that the number of words in Wikipedia has grown by 1% a month since January 2010, then Wikipedia would be worth around $2.2 billion at the end of 2011.

This is more than the GDP of several countries. If, for example, Sierra Leone or Bhutan wanted to make something as comprehensive as the beloved encyclopedia then they would have to give up all of their income for an entire year and they still wouldn’t be able to afford to pay writers enough.

If we assume that the majority of the words are written by registered users then each of the 750,000 users would have to be paid $3,035 for their efforts. Yet Wikipedia has managed to put together the largest database of human knowledge in history without paying writers a dime.

What’s fascinating is that $2.2 billion is arguably the lowest and most conservative estimate of the English Wikipedia’s net value. It’s assuming that Wikipedia is just the sum of its parts. But in reality it’s much more than that and while a company could, conceivably, create something similar to Wikipedia by forking over $2.2 billion (although it would not have the same dynamism), they would likely have to pay orders of magnitude more to purchase the entire encyclopedia itself.

Read our other editorials to find out how many Zombies it would take to defeat Napoleon’s forces as well as a look at Pocahontas as a potential candidate for the Nobel Peace Prize. Or follow us on Twitter to get the latest updates from Centives.

*Freelance writers can be paid as little as 10 cents a word. Most serious magazines that pay on a per-word basis pay their writers somewhere between $0.60 and $1.50 a word.