Condensed concepts

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

Condensed matter physics and sociology are both about emergence. Phenomena in sociology that are intellectually fascinating and important for public policy often involve qualitative change, tipping points, and collective effects. One example is how social networks influence individual choices, such as whether or not to get vaccinated. In my  previous post , I briefly introduced some Ising-type models that allow the investigation of fundamental questions in sociology. The main idea is to include heterogeneities and interactions in models of decision.  What follows is drawn from Sections 2 and 3 of the following paper from the Journal of Statistical Physics.  Crises and Collective Socio-Economic Phenomena: Simple Models and Challenges  by  Jean-Philippe Bouchaud Bouchaud first considers a homogeneous population which reaches an equilibrium state. This is then described by an Ising model with an interaction (between agents) J, in an external field, F that describes the incentive for the a

World news is full of dramatic and unexpected events in politics and economics, from stock market crashes to the rapid rise of extreme political parties. Trust in an institution can evaporate overnight. The world is plagued by " wicked problems " (corruption, belief in conspiracy theories, poverty, ...) that resist a solution even when considerable resources (money, personnel, expertise, government policy, incentives, social activism) are devoted to addressing the problem.  Here I introduce some ideas and models that are helpful for efforts to understand these emergent phenomena. Besides rapid change and discontinuities, other relevant properties include herding, trending, tipping points, and resilient equilibria. Some cultural traits or habits are incredibly persistent, even when they are damaging to a community.  I now consider some key elements for minimal models of these phenomena: discrete choices, utility, incentives, noise, social interactions, and heterogeneity. Discr