A study of 14 of the largest subway networks around the world has discovered that they all tend to end up in common network structure, once you consider the distribution of lines, stations and total distances. For example, the number of stations was proportional to the square of the number of lines. The core of the networks had a similar number of neighbors in the network, with about half of the stations found outside the core. Most interesting, the different networks all appear to converge to this optimal structure over time, regardless of how the network began.
So what has this got to do with patents? Here at Ambercite, we believes that patents are best asssessed in terms of their role in the network. We have only recently republished the image below from our smartphone report, but it remains an excellent example of how individual patents can be assessed in terms of the patents around it.

In this particular case, we can see how this particular Motorola patent is connected to a broad range of backward citattion patents, but also there is a broad range of foward citations links to a strong clusters of key Apple patents.
However not all patents have this same degree of valuable connections. In fact, virtually all of the networks we have studied have converged to a similar distribution of patent value, (again previously presented) in which only a small number of patents have the majority of the value.

So when the academic study found that subway networks too converged to a common network structure, this did not surprise us, and in fact we would expect to see convergence in a variety of network structures, such as for example the Delta airline route map, which is a great example of networks in daily life . We await with interest to see the details of these other types of networks being published.
