Whether people want to get married or not - it is their choice. Whether couples want to have children or not - it is their choice (and luck/fate). Economists and other social professionals may have their opinions, they have the right to express their views. How many children a family has, or when, that is for the couple to decide. No one else has the right to tell them when, how, how many and all that. It is their own lives.
Cheers!