A bridge between liquids and socio-economic systems: the key role of   interaction strengths
  One distinctive and pervasive aspect of social systems is the fact that they comprise several kinds of agents. Thus, in order to draw parallels with physical systems one is lead to consider binary (or multi-component) compounds. Recent views about the mixing of liquids in solutions gained from neutron and X-ray scattering show these systems to have a number of similarities with socio-economic systems. It appears that such phenomena as rearrangement of bonds in a solution, gas condensation, selective evaporation of molecules can be transposed in a natural way to socio-economic phenomena. These connections provide a novel perspective for looking at social systems which we illustrate through some examples. For instance, we interpret suicide as an escape phenomenon and in order to test that interpretation we consider social systems characterized by very low levels of social interaction. For those systems suicide rates are found to be 10 to 100 times higher than in the general population. Another interesting parallel concerns the phase transition which occurs when locusts gather together to form swarms which may contain several billion insects. What hinders the thorough investigation of such cases from the standpoint of collective phenomena that we advocate is the lack or inadequacy of statistical data for, up to now, they were collected for completely different purposes. Most essential for further progress are statistics which would permit to estimate the strength of social ties and interactions. Once adequate data become available, rapid advance may be expected. 
Bertrand M. Roehner