It’s hard to model serendipity in a rational choice framework.  For example, people say that the web’s ability to focus your attention on subjects you like prevents you from being exposed to new stuff and that makes you worse off.  That may be true, but it could never be true in a rational framework because if you wanted exposure to new stuff you would choose that.  (I am leaving out market structure explanations, i.e. the market for serendipitous content may shrink.  That’s beside the point I am making and anyway I would guess exactly the opposite.  I can always take advantage of the increased diversity in content by supplying my own randomness.)

But here’s a version of serendipity that may be rationalized.  I have started reading blogs in my Google reader using the “All Items” tab where all the articles in all the blogs I subscribe to are listed in a flat format in chronological order, rather than blog-by-blog.  I have found a non-obvious effect of serendipity:  not knowing which blog I am reading and just reading the article prevents me from approaching it with expectation of the author’s prior biases, etc.  I recommend it.

For some kinds of information it may be beneficial to hide the source.  For example, pure rhetoric.  My ability to judge whether it is convincing or not is based purely on the logical connections between premise and conclusion and my prior beliefs about the plausibility of the premises.  Knowing the author of the rhetoric provides no additional information.  And if, for psychological reasons, knowing the source biases my interpretation then I am strictly better off having it hidden from me.  (At least temporarily)

You will complain that by appealing to psychological biases I have departed from the rational choice framework.  But I think there is a useful distinction between rational choice, and rational information processing (if the latter even has any meaning.)  If I can be expected to choose my sources rationally then there is no role for serendipitous exposure to new sources, even if I make errors in processing information.  But rational choice together with (self-aware) processing errors can justify keeping the source hidden.

(Drawing by Stephanie Yee.)