CollEc provides rankings by co-authorship centrality for
authors registered in the
RePEc Author Service.

We have centrality rankings.

- Closeness ranking looks at how far an author is, on average, to all others economists.
- Betweenness ranking looks how many times an author appears on average on shortest paths between all other economists.

You can use the authors linked to by the rankings to find paths
to any of the over 41,000 economists in the network. If you are
in the network use a RAS handle to find yourself, and from you,
find the path to anybody else in the network.

We don’t have current statistics. A count on 2018‒08‒15 found we
have 1715265339 paths under management. Our computer constantly
works to update them. With constant computing resources and a
growing network, there is a growing gap between reality and the
results. If the network would growing, then our calculation
would converge to true values.

There is some documentation.