Network paradoxes galore!

The nCovid-19 saga really scares me. Yes, the virus and its highly contagious nature, is one part of the scare. The other part of the scare is our response to it.

Yes, we need aggressive measures to "flatten the curve" and enforce social distancing, hand washing, etc. But the way we are going about implementing it, has the potential to make the problem worse, with long term collateral damage.

Let me explain.

One of my primary areas of research is in complex social networks and its emergent properties. What we are seeing today is almost a textbook case of all kinds of network paradoxes in action-- Braess' paradox, Cobra effects, Streisand effects, Prisoners' dilemma, bull-whip effect, etc. Just about all of these, refer to situations where a given policy or norm is adopted towards achieving a particular goal, but the end result would be exactly the opposite.

It is somewhat like the popular saying that, "The road to hell is paved with good intentions."

One of the good things India did was to act early and put in screening procedures in place, as early as mid Jan, when even the WHO recommendation said the following:

WHO does not recommend any specific health measures for travellers. It is generally considered that entry screening offers little benefit, while requiring considerable resources. In case of symptoms suggestive to respiratory illness before, during or after travel, the travellers are encouraged to seek medical attention and share travel history with their health care provider. WHO advises against the application of any travel or trade restrictions on China based on the information currently available on this event.

For a long time, India, despite sharing a border of more than 3000 kms with China, and large extents of business interactions, had one of the lowest incidences of Corona infections.

Yet, in the last week or so, we have seen increasing rates of Corona positive cases, and increasing rates of panic responses to the crisis.

For instance, the Prime Minister announced a "Janata curfew" yesterday so that people stayed home and practiced social distancing. He also implored the citizens of the country to applaud the people in the frontline at 5:00pm. This was a great success in the sense that a lot of people came out to applaud and the sense of national commune was palpable. But what also happened was that yesterday at 5:00pm, there was a celebration of sorts in several places, with people gathering in large groups to applaud and improve morale! Thus, creating a situation that was exactly the opposite of what was intended.

Given that the virus shows no signs of abating, today, the government issued a lockdown order all over the country, and cancelled public transport, inter-city transport and even domestic air travel starting tomorrow. What was the response from the population to this? As current news reports go, our highways leading out of the city are packed with people trying to leave the city to their home towns before everything is locked down. Busses and trains are packed with people on panic commutes. I do hope that the virus knows that the lockdown starts from tomorrow, and that it should not infect anyone today!

In addition to the above, there are other kinds of social panic reactions. Nurses who are working on the frontline and staying in rented apartments or paying guest accommodations were in some cases, asked by their landlords to vacate their premises in fear of the Corona! That doesn't really help in our struggle against the virus.

Then there were reports of racial attacks against people from the North-East of India, because they look like Chinese!

And yes, there are already Corona related suicides!

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I am completely aware that the situation is very serious and the virus is highly contagious with an R0 rate of about 3.0. The fact that we need quick, large-scale measures are also well taken. 

But the approach we are taking towards this problem may not only have the opposite consequences, it may also create a large collateral damage. 

There are already talks of imposition of emergency and draconian measures to keep people home. But "draconian measures" are no guarantee that the infection does not spread. Draconian measures are meaningless if they are not implemented properly. In order to implement draconian measures, some segment of the population should necessarily go out and implement it. The system of people implementing the draconian measures may themselves act as the carriers of the virus passing them from one isolated community to another. 

Complex networks of self-interested agents (human societies is an example) are replete with such emergent properties that are very counter-intuitive. These "network paradoxes" are not some academic curiosity to banter about when people in the frontlines are battling the disease. These are real consequences that can lead to systemic collapse that can greatly amplify the already serious crisis. 

So how do we deal with these paradoxes? What should we do to take swift action without the resultant panic reactions? 

There are no simple answers to this question. But some heuristics can definitely help. 

We know for example, human social networks are not uniformly random. A person is not equally likely to interact with just about anyone else. Social networks are known to be clustered, with a property called triadic closure. In simple terms, what this means is, if a person A interacts with two other persons B and C, then B and C are likely to interact with one another, the more the interaction strength between AB and AC. 

If we work out the math, this leads to a society of several clusters, with some connections between the clusters-- which are called the "bridges". These bridges are critical elements in diffusing something across clusters-- be they ideas or pathogens. 

Similarly, human societies are known to display a "scale free" and "small world" property. What this means is that, despite the complex and clustered nature of human social connections, human societies tend to have small degrees of separation. This means that we can connect anyone to anyone else with a small number of hops. This is where the popular notion of "six degrees of separation" comes from. 

A small world network is bad news in the face of a contagion. This is precisely why this virus that originated in a city in China has now become a global pandemic within a few weeks. 

But how does a network get its small world property, if it is also characterised by clusters due to triadic closure? Remember, we said that not everyone is equally likely to interact with everyone else. So how does the small world property arise? 

The answer to this is the existence of hubs in any social network, at any scale. Hubs are network nodes that connect to a large number of other nodes. The number of large hubs with respect to the number of nodes in the network remains more or less the same, regardless of the scale in which we are looking at a network (thus the name "scale free network"). 

Hubs are the primary connectors between disparate parts of the network. If we are to contain a contagion, the first thing we need to do is to shut down major hubs like airports, bus stations, railway stations, etc. or tightly regulate their traffic. Ironically, in many airports across the world, people were made to queue up in large lines for mandatory screening, which would have only increased the chances of more contagion within the place. A better strategy would be to first reduce the traffic in the hub, and divert airplanes to several other nearby airports and spread out the crowd and mandatory testing. 

Similarly within a city, if we mark out several localities, we can see that once WFH and an advisory lockdown is in place, most people would stay within the locality. Go to each locality regulate entry and exit on all the roads that connect it with other localities. Thoroughly check and sanitise every vehicle and person that cross these "bridges" between localities. Within each such sanitised locality, people should be able to move around freely-- subject of course, to periodic and proactive testing. 

Much of the exacerbation of the situation happens due to panic psychological reactions from people that impair their sense of sound judgment. One such reaction is psychological denial. The more we push in a sense of seriousness and urgency through all media channels, the faster this state of psychological denial is likely to set in. Once there is a sense of psychological denial or fatalism, people tend to act in bigoted, vindictive and reckless manner, like for example, the several cases of Corona-infected people in China, deliberately infecting others. 

Human free-will and psychology are central elements of social responses to crises. It is important to understand what could happen in response to a crisis response, rather than just what should happen.