What a silly article. PageRank is based on eigenvector centrality[1], which is one of a number of well-understood centrality measures that have been around for a long time. Google's innovation was noticing the importance of the link structure of the internet and knowing to apply EC to it - not inventing the graph theory underlying EC.<p>Edit: and knowing to apply EC to that graph structure.<p>[1] <a href="http://en.wikipedia.org/wiki/Centrality" rel="nofollow">http://en.wikipedia.org/wiki/Centrality</a>
I'm really curious how on Earth they tracked all these down. Imagine how many obscure papers were published they didn't look through that had the same idea.<p>>One important question is: what is the value of each sector when they are so tightly integrated? Leontief’s answer was to develop an iterative method of valuing each sector based on the importance of the sectors that supply it.<p>That's actually pretty interesting. But I think in economics a circular graph doesn't really make sense, does it? It's more two ways with one person trading with another person (with any number of intermediate nodes.)