  Substantial empirical research has shown that the level of individualism vs.
collectivism is one of the most critical and important determinants of societal
traits, such as economic growth, economic institutions and health conditions.
But the exact nature of this impact has thus far not been well understood in an
analytical setting. In this work, we develop one of the first theoretical
models that analytically studies the impact of individualism-collectivism on
the society. We model the growth of an individual's welfare (wealth, resources
and health) as depending not only on himself, but also on the level of
collectivism, i.e. the level of dependence on the rest of the individuals in
the society, which leads to a co-evolutionary setting. Based on our model, we
are able to predict the impact of individualism-collectivism on various
societal metrics, such as average welfare, average life-time, total population,
cumulative welfare and average inequality. We analytically show that
individualism has a positive impact on average welfare and cumulative welfare,
but comes with the drawbacks of lower average life-time, lower total population
and higher average inequality.
