Pondering Social Contagions in the 19th Century

If only they knew about social contagions...

The winner of Answers magazine's big Question Competition of 1888 was Mr. E Bond of Bloomsbury, who submitted this entry: pic.twitter.com/0kU0Mwxlqj

— Dr Bob Nicholson (@DigiVictorian) December 28, 2018

And here is the beginning of the thread.

In 1888, Answers magazine ran a prize competition in which readers were challenged to send in 'The Most Interesting Question On Any Subject.' Reading through the results is like looking at Victorian Britain's Google search history...

Thread 👇👇👇: pic.twitter.com/Z4aQDTtM3E

— Dr Bob Nicholson (@DigiVictorian) December 28, 2018

Tales from the ArXiv: Motto: "Somebody has to Study this Shit!"

Motto: Somebody has to study this shit!

And I mean this literally: the title of the paper is "An Agent-Based Model for Bovine Viral Diarrhea".

Update: Normally, I hate it when papers are full of bullshit. However, I may need to make an exception in this case.

'Working Paper' in Collaboration with International Monetary Fund: "Evolution of the Global Financial Network and Contagion: A New Approach"

A 'working paper' from a collaboration with folks from the International Monetary Fund (IMF) came out today. You can download it from this website. We also hope to submit a version of this work to a journal for publication. Here are some details.

Title: Evolution of the Global Financial Network and Contagion: A New Approach

Authors: Yevgeniya Korniyenko, Manasa Patnam, Rita Maria del Rio-Chanon, and Mason A. Porter

Abstract: This paper studies the interconnectedness of the global financial system and its susceptibility to shocks. A novel multilayer network framework is applied to link debt and equity exposures across countries. Use of this approach—that examines simultaneously multiple channels of transmission and their important higher order effects—shows that ignoring the heterogeneity of financial exposures, and simply aggregating all claims, as often done in other studies, can underestimate the extent and effects of financial contagion.The structure of the global financial network has changed since the global financial crisis, impacted by European bank’s deleveraging and higher corporate debt issuance. Still, we find that the structure of the system and contagion remain similar in that network is highly susceptible to shocks from central countries and those with large financial systems (e.g., the USA and the UK). While, individual European countries (excluding the UK) have relatively low impact on shock propagation, the network is highly susceptible to the shocks from the entire euro area. Another important development is the rising role of the Asian countries and the noticeable increase in network susceptibility to shocks from China and Hong Kong SAR economies.

Congratulations to Dr. Se-Wook Oh!

Congratulations to my D.Phil. student, Dr. Se-Wook Oh, who has officially earned his doctorate from the Mathematical Institute at University of Oxford. (Jon Chapman was nominally added as a local co-supervisor after I moved to UCLA.) His thesis, in corrected form, has officially been approved.

The title of Se-Wook's thesis is Complex Contagions with Lazy Adoption. You can read about some of Se-Wook's work in our joint paper, which was published recently in Chaos.

"Complex Contagions with Timers"

A new paper of mine just came out today. This paper was such a pain to write and the page proofs were also a royal pain, so it's a relief that it's finally out. Here are the details.

Title: Complex Contagions with Timers

Authors: Se-Wook Oh and Mason A. Porter

Abstract: There has been a great deal of effort to try to model social influence—including the spread of behavior, norms, and ideas—on networks. Most models of social influence tend to assume that individuals react to changes in the states of their neighbors without any time delay, but this is often not true in social contexts, where (for various reasons) different agents can have different response times. To examine such situations, we introduce the idea of a timer into threshold models of social influence. The presence of timers on nodes delays adoptions—i.e., changes of state—by the agents, which in turn delays the adoptions of their neighbors. With a homogeneously-distributed timer, in which all nodes have the same amount of delay, the adoption order of nodes remains the same. However, heterogeneously-distributed timers can change the adoption order of nodes and hence the “adoption paths” through which state changes spread in a network. Using a threshold model of social contagions, we illustrate that heterogeneous timers can either accelerate or decelerate the spread of adoptions compared to an analogous situation with homogeneous timers, and we investigate the relationship of such acceleration or deceleration with respect to the timer distribution and network structure. We derive an analytical approximation for the temporal evolution of the fraction of adopters by modifying a pair approximation for the Watts threshold model, and we find good agreement with numerical simulations. We also examine our new timer model on networks constructed from empirical data.

Early Warning Signs for this Year's Epidemic

And so it begins... pic.twitter.com/9nwjb2mSes

— I❤80s (@IL0VEthe80s) October 26, 2017