Advantages of having a small family

Advantages for whom ? Generally,   in a smaller family the resources are distributed among fewer people, which means that the children can get a better education and  more support and the parents don't need to work us much (e.g. double shifts) to support their family. For the whole state, a 2+2 model is also the most sustainable,  where there are no drastic differences in population age over time:the number of people stays constant if everyone has around 2 children.

What biome? i can just which