You To Me, You To Them - More About Network Effects

Not that we have to be reminded, but COVID has certainly reminded us of the fact that we are all connected, in varying degrees, and have an impact on each other.  This reminder from a pandemic shouldn’t be a surprise since some of the earliest and best work on real network effects between people has been done by public health experts.

The now classic 2009 book, Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives, by Nicholas Christakis and James Fowler showed the ways that our networks with other people affect, among other things, our emotions, political views, wealth, and health (even body weight).  Given that one of the most important origins of the study of human networks was in public health, it won’t be surprising that Christakis, who specialized in public health, was particularly interested in the long-running Framingham study of health.

For the rest of us, who are not in public health, it would seem that viral pictures and memes on the net form our understanding of network effects.  But there is much more to these connections than simply passing images and memes to one another – even much more than passing diseases to each other.

There have been, at least, three relatively recent books that help describe in more useful and original detail the impact of each of us on each other.  The ideas in these books apply not just to health, but to the economy, business and career success as well.

Robert H. Frank is one of the most creative and insightful economists around.  His book this year, “Under the Influence: Putting Peer Pressure to Work”, is a review of behavioral economics, with an emphasis on network effects.  That includes how it is not only the absolute value of goods and wealth that motivate economic behavior, but our ownership of goods relative to others.  Rather than maximizing wealth, per se, many people want to maximize their relative position.  Thus, he points out that having another billion dollars is not so important to the richest man, as long as he is richer than other men.  (This has important implications for tax policy and other public policies, which he discusses the book.)

Matthew O. Jackson’s 2019 book “The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviors” extends the work of Christakis with explanations of network measures and phenomena in the economy.  Those economic phenomena include two very relevant to our times – economic inequality and economic crises (or, to put it more simply, economic bubbles that burst).  He shows how the well-known tendency of people to connect with others who are similar to themselves can generate inequality.

In an elaboration of the old adage – “it’s not what you know, but who you know” – Jackson also describes the various ways that our position in our networks influence our behavior and outcomes for us in those networks.

Of course, you may know some people very well, like family, and others not so well.  As Duncan Watts showed in his 2004 book, “Six Degrees: The Science of a Connected Age”, the people you don’t know so well – those with whom you have weak ties – can connect you to almost anyone else on the globe in just a few steps.

One popular application of that idea is that it is weak ties that are the key to success in finding out about job openings or getting major initiatives accomplished in a large organization.  We’ve all heard about the importance of “networking” in career success.  But, like all such popular ideas, the importance of weak ties has been applied to too many situations, some of which are inappropriate.

That is the point of Damon Centola’s 2018 book, “How Behavior Spreads: The Science of Complex Contagions”.  He provides a more nuanced view of the best time to use weak or strong ties.  If the goal is to quickly pass information – such as about a job opening or a cute meme – then weak ties will indeed do the best job.  However, if the goal is to change the behavior of people, something not as casual as passing along a joke, then having someone lead the change in a networks of strong ties are more effective.

This post can only provide a summary of three of the most interesting authors.  It is worth reading each of these books as well as other books and articles that have contributed to our understanding of this important, but complex, subject of human interactions.

Expect more new knowledge in the future.  After all, there is now a lot of and a growing amount of big data about human interactions that can provide a gold mine to be explored with network analytics, but more generally machine learning and AI.

A final thought … You would expect that the importance of these phenomena of social influence would be built into many models of individual human behavior and then aggregated, network style, into larger models to understand macro phenomena and trends.  Curiously, such network-informed models are few and far between – but that’s a topic for a future blog post.

© 2020 Norman Jacknis, All Rights Reserved

 

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