How many children should have a family?

As we know in civilized countries the birth rate is declining, for years. In contrast, in third world countries (including India and Indonesia) birth rate is increasing. And not only cultural differences make a difference.
Usually, both young Europeans and Americans believe that a career is more important than family. Career in poor countries is not so important.
How many children to have?

Hard to say. Probably 2. Why 2? Because it is much easier raised and educated two children instead of 3 or 4. And, a single child it will feel alone.
Plus, from an average of 2-3 children per household, the population (number)
  will remain constant.

Simple questions require simple answers. This site is meant to be a positive response to this need. answer-blog.blogspot.com