This is a major factor. I have a 2-year old girl with another baby imminent. I have 6 households of my family all within a 20 minute drive. Like you say, aside from the practical benefits and savings on childcare, clothing etc., the psychological benefit of knowing we have that support is immeasurable.

Given the impending arrival of my second child, I find myself wondering about those with less support. What does a pregnant single mother of one do when she goes in to labor? Where does her child go? In to state care??

I have great respect for parents with less support than I have.