<...> Unfortunately, this cross-fertilisation did not really follow through, at least not on a large scale, in spite of the involvement of larger and larger cohorts of physicists in the development of what is now called "econophysics" and "sociophysics". Until recently, mainstream economists have essentially muddled through along the same well-trodden path, developing monetary policy tools based on the idea that agents are rational calculators with infinite foresight, who optimize their "utility function" assuming others will do the same. In 2003, Robert Lucas - one of the dons of Rational Expectations and Nobel Prize recipient in 1995 - claimed that "the central problem of depression prevention had been solved". We know all too well what happened in 2008. <...>

Or so writes J. P. Bouchaud in [1], which is one of the best recently written introductions to econophysics and sociophysics. We invite you to read it on arxiv (see reference for the link) or find it on Europhysics News.

References

• J. P. Bouchaud. Econophysics: Still fringe after 30 years? To appear in Europhysics News. arXiv:1901.03691 [physics.soc-ph].

Last time we have introduced you to the Sznajd model. We have also mentioned that this model was rather popular in Sociophysics around the beginning of the XXI century. This time I wanted to introduce you to one the modified Sznajd models, but I have misread the article [1]. Well, accidents happen in science from time to time...

Nevertheless the "misread" model also looks rather nice, so I have decided to still present it. Next time I'll introduce you to the original version of this "misread" model.

Recently we have introduced you all to the hierarchical voting model by Serge Galam. Now let us consider a very similar idea - what if before voting the people would discuss the issue in question in the small groups? Experiments conducted by social scientists Mariano Sigman and Dan Ariely seem to indicate that such procedure allows for crowds to become a bit wiser. Watch the following TED video in which Mariano Sigman describes both the concept and its implementation as experiment.

Sznajd model, also known as united we stand, divided we fall model, is another classical model in opinion dynamics. It was proposed in 2000 by two Polish scientists in [1] and since then it was heavily studied both by various groups of sociophysicists. It was used not only in the usual generic scenarios (e.g., exploring how fast the opinions converge), but also helped to predict Polish elections of 2015 [2].

It is often said that turning up to vote is not quite rational behavior, because the probability that your vote would decided the outcome is minuscule. Opponents of such outlook say that it is rational to vote, because you might want to show support for the political system (democracy) or to avoid the regret.

I guess at least one person in Byron-Bethany irrigation district in California feels such regret, because the last election outcome in this district was decided by three random rolls of the twenty sided dice. More details in the CBS video below.