Hysteresis, hype, niches, nudges and social change

The world is a mess. Most people want a better world. Sometimes nothing changes. Sometimes things change incredibly rapidly. Sometimes changes are positive. Other times the change is negative. Often this change is unanticipated, even by experts who have been studying the relevant topic for decades. Wicked problems are things that seem to be incredibly resilient to change. Examples of rapid changes that were (largely) positive and unanticipated were the peaceful collapse of the former Soviet empire, smoking in public becoming taboo, and increased public concern about climate change. Examples of negative changes include the rise of Trumpism, misinformation on social media, and the global financial crisis of 2008.

Many people in government, public policy, NGOs, and social activists want to implement policies and take actions that will produce outcomes that (they believe) are positive. Here I discuss some basic but very important insights from "social physics", such as discussed in my previous two posts.

Suppose the system of interest can be modelled by some type of Ising model where the pseudospin corresponds to two choices (good and bad) for each agent in the system. The policy maker wants to change something such as increase the incentive for agents to make the "good" choice. There are two qualitatively different possible behaviours and they are shown in the Figure below (taken from Bouchaud). 

The vertical axis is the "magnetisation", i.e, the fraction of agents who make the good choice. The horizontal axis is the "external field", i.e, the level of incentive provided for agents to make the good choice. 

Case I. Smooth curve (blue). This occurs when the interaction between agents is weaker than some threshold strength. Suppose that a small but not insignificant minority of agents are already making the good choice and then incentive is increased slightly. If one is near the steep part of the blue curve then this "nudge" can produce a desired outcome for the society.

Case II. Discontinuous curve (red). This occurs when the interaction between agents is greater than some threshold strength. People's choices are influenced more by their friends than by what the government or an NGO is telling them to do. Then one has to provided very large incentives to get a change in agent choice, far beyond the incentive required for a single isolated agent. The system is stuck in a state that is not good for the society as a whole. It is a metastable state, as shown in the figure below.

On the other hand, if the "polarisation field" is sitting near a critical value (5 in the figure, a tipping point), then a "nudge" can lead to a dramatic change for good. 

I think there are important implications for social activists of all stripes. Realistic expectations are key.

1. Don't expect even the best-designed and well-intentioned policy or action to necessarily have the impact you hope for.

2. Be sceptical about hype and ideology. In the public space there are a lot of claims, whether from political parties, pundits, or NGOs, that if we just do X (change this law, donate money, do what my book says, ...) then the good Y will inevitably follow.

The problem with unrealistic expectations is that they lead to disappointment, disillusionment, and burnout. People give up. Then the next fad or "silver bullet" comes along...

Inspired by a rugged landscape perspective, a better and more sustainable approach is that of learning and adaptation. One identifies what one thinks the best "nudge" is, tries something, evaluates the effect, adapts, and tries out some new ideas. One does not claim or expect the first few iterations to produce a significant desired effect. Here, somewhat "random" sampling of the landscape may help. Here a diversity of perspectives and methods can play a positive role. A more concrete version of this argument is in a paper concerned with public health initiatives. Rugged landscapes: complexity and implementation science, by Joseph T. Ornstein, Ross A. Hammond, Margaret Padek, Stephanie Mazzucca & Ross C. Brownson 

Postscript. After posting this I remember reading a recent article in The Economist pointing out how nudges often do not work.

Evidence for behavioural interventions looks increasingly shaky 

The academic literature is plagued by publication bias 

It references three recent Letters in PNAS, including this one, that come to the opposite conclusion to an earlier PNAS paper.

The effectiveness of nudging: A meta-analysis of choice architecture interventions across behavioral domains 

Stephanie Mertens, Mario Herberz, Ulf J. J. Hahnel, and Tobias Brosch