摘要
While population density represents an important socio-economic parameter, its role is rarely studied in the economic literature （contrary to natural sciences）. Population density plays an important role in harvesting societies, i.e. those that depend on agriculture and natural resources. With the development of industry and services and emergence of urban areas, population density becomes less economically important unless we consider aspects related to pollution. There exists a phase transition between rural and urban area which makes population density less important in urban area contrary to rural. However, the economic influence of population density in harvesting societies is also not straight forward. Too high population density decreases the natural endowment per capita, but eases the development of infrastructure, leading to existence of an optimal population density for economic growth. It also influences the demand for a monopolistic product, where too little density can lead to non-survival of a monopoly. Emergence of ethnic communities is based on more cooperative behavior in the case of low cultural and physical distances. At the same time, higher probability of large projects （like infrastructure） leads to development of cooperative behavior in the society. Elaboration along these lines leads to the conclusion that population density positively correlates with individualistic （non-cooperative, non-altruistic） behavior, through less time spent in cooperative infrastructure projects and higher frequency of meetings between individuals that with some probability lead to non-cooperative games.
