Modelling population distribution

Modelling population growth in each tile is relatively easy: it depends on birth rate and death rate. The former depends on cultural factors until the discovery of contraception, whilst the latter depends on food availability, clean water, environmental conditions (e.g. temperature, tropical diseases), level of medical technology and distribution of medical technology.

Modelling the formation of cities and migration from rural to urban areas is more tricky. One way to do this would be to assume employment is the only driver of migration (a not-unreasonable assumption). So each rural tile would have a number of jobs, which would depend on the available agricultural land and technology level (higher technology levels need fewer people per acre). Any people not employed migrate to the nearest city.

Per tile data:

Jobs

Food production

Population

In rural tiles there are a fixed number of jobs

Excess food production goes to urban squares