Q: I own a painting by a California artist, looked up his name in a dictionary of California artists, and found quite a bit of biographical information. I then took the painting to an art dealer and he told me it was worth only several hundred dollars. I thought it would be worth a lot more than that based on the size of the listing. Why isn't it?
A: Don't confuse the size of an artist's listing in a dictionary or encyclopedia with the monetary value of his art. Long listings do not automatically mean big bucks; short ones don't always mean pocket change. Fair market values are based far more on supply and demand among dealers, collectors, and the state of the art market than they are on the amount of information that you find in biographical references.
The more that's written about an artist, the more his art is generally worth, but the two factors are ultimately independent and there are plenty of exceptions to this rule. In the scholarly art community, the length of an artist's listing or mention in a book is often based on the availability of career data. For example, if a researcher gets an extensive interview from the descendants of a minor artist, he can write a large listing. Even though that artist's work is worth little in the marketplace, his accomplishments are now documented in detail.
Another instance where lots of published material may have little relationship to dollar value is when galleries produce books or exhibition catalogues about artists that they represent. These aren't necessarily published because the artists are famous or their art is significant, but rather because they make great sales tools. Once again, the available data about the artists may be impressive, but their art may have little value outside of the galleries that represent it. Galleries self-publish art books and catalogues all the time in order to increase the attractiveness of their art to collectors.
Regarding your situation, the California artist dictionary that you used to research your artist was written by a scholar, not an art dealer. He didn't care about market values or take them into consideration when researching and compiling his book. His job was to track down biographical information, and document artists, art movements, and art history in the state of California.
Use auction record compendiums, art dealers, art appraisers, price guides, and online databases when researching the dollar values of art. Use scholarly reference works for obtaining biographical data and learning what artists accomplished during their careers. Using one to evaluate the other is like comparing apples and oranges.