In poor countries, more people live in subsistence farming and the overall economy is predominantly agrarian. In such conditions, every child in the family is an additional assistant and an extra pair of working hands from childhood. That is, many children here are not a burden, but a family asset.

As the country develops, more people live in cities and a child turns from a family asset into an expensive and long-term project, so in developed countries it is normal to have one, maximum two children in a family.