I think this is only partly true. It's expensive to have a child and I think there are a lot of people out there who think they cannot afford a child. However, I also think that the declining birthrate is connected to women being able to say no these days while they didn't really have a choice a century ago. Women were expected to have children once they were married. I don't think the question of whether someone wanted to have a child or not never came up. But women's rights have changed, and children aren't needed to take care of their parents at old age anymore. So, now if you don't want a child, you can not have a child.