Average happiness in big cities with more than 250,000 inhabitants is, in the USA, lower than average happiness in towns and in the country. Adam Kozaryn offers several explanations. One explanation is that core characteristics of cities, such as size, density and heterogeneity lead to a deterioration of social relations. This explanation is insufficient because average happiness in cities can also be relatively high, as is the case in poor nations, compared to happiness in towns and in the country. Important factors like relative safety and the availability of services have to be considered additionally. A second explanation is that capitalism plays a more dominant role in cities, with similar negative effects. This explanation is also insufficient because the negative effects of capitalism are not limited to cities. A more plausible explanation is that average happiness in American cities is relatively low, because of the interaction of their core characteristics and capitalism. More people should live in smaller places, but this is impossible. There are too many people and big cities are needed to minimize their ecological footprint. Overpopulation is the root of the problem. A discussion about the maximum size of the population is needed. There is no reason to fear for a negative impact on individual freedom, but people can pay attention to this discussion if they make up their mind about having children.