Populist responses to matters of social concern are considered in a framework like that of Acemoglu and Robinson’s ‘narrow corridor’ that supports liberty and justice. We discuss the risk that such responses could result in a country being pushed out of this narrow corridor—and, if so, with what long-run consequences. We conclude that a political system of ‘checks and balances’ can play a key role in keeping the society within the narrow corridor; but it is incumbent on the existing political system to confront the issues of populist concern so as to come up with creative solutions.

We consider a classic competing-species model with the rates changed to include Gaussian white noise. We show that if the noise is not too large, then the stochastic version is ergodic. An explicit relation between the noise and the original competing-species parameters gives a sufficient condition for ergodicity.

We investigate a random collision model for competition between types of individuals in a population. There are dominance relations defined for each pair of types such that if two individuals of different types collide then after the collision both are of the dominant type. These dominance relations are represented by an oriented graph, called a tournament. It is shown that tournaments having a particular form are relatively stable, while other tournaments are relatively unstable. A measure of the stability of the stable tournaments is given in the main theorem.