"Causal inference in social networks: A new hope?" (Friday at the Ann Arbor Statistics Seminar)

Attention conservation notice: Self-promoting notice of a very academic talk, at a university far from you, on a very recondite topic, solving a problem that doesn't concern you under a set of assumptions you don't understand, and wouldn't believe if I explained to you.

I seem to be giving talks again:

"Causal inference in social networks: A new hope?"

Abstract: Latent homophily generally makes it impossible to identify contagion or influence effects from observations on social networks. Sometimes, however, homophily also makes it possible to accurately infer nodes' latent attributes from their position in the larger network. I will lay out some assumptions on the network-growth process under which such inferences are good enough that they enable consistent and asymptotically unbiased estimates of the strength of social influence. Time permitting, I will also discuss the prospects for tracing out the "identification possibility frontier" for social contagion.

Joint work with Edward McFowland III

Time and place: 11:30 am -- 12:30 pm on 8 February 2019, in 411 West Hall, Statistics Department, University of Michigan

--- The underlying paper grows out of an idea that was in my paper with Andrew Thomas on social contagion: latent homophily is the problem with causal inference in social networks, but latent homophily also leads to large-scale structure in networks, and allows us to infer latent attributes from the graph; we call this "community discovery". Some years later, my student Hannah Worrall, in her senior thesis, did an extensive series of simulations showing that controlling for estimated community membership lets us infer the strength of social inference, in regimes where community-discovery is consistent. Some years after that, Ed asked me what I was wanting to work on, but wasn't, so I explained about what seemed to me the difficulties in doing some proper theory about this. As I did so, the difficulties dissolved under Ed's questioning, and the paper followed very naturally. We're now revising in reply to referees (Ed, if you're reading this --- I really am working on it!), which is as pleasant as always. But I am very pleased to have finally made a positive contribution to a problem which has occupied me for many years.

Constant Conjunction Necessary Connexion; Enigmas of Chance; Networks; Self-Centered