[originaltext]The traditional American family used to have a working father, a

The traditional American family used to have a working father, a housewife-mother, and two or three children. But in the last 25 years, this picture has changed. Now we have many different kinds of families and living situations besides this traditional one. For example, there are many single mothers and single fathers who are raising children by themselves. There are married couples who decide that they don’t want any children. Sometimes adult children who have been living alone for a long time come back and live with their parents again. You can also find groups of older people sharing a house in order to save money. And there are many other examples of new types of families in this country.
Why has the traditional family changed so much? Well, the reasons are both social and economic. First, as you know, the divorce rate is high in our culture; as a result, we have many single-parent families. Second, there is unemployment among young adults. If they cannot find a job, many times they return home and live with their parents again. But of course the most important reason for the changes in the American family is all American women are now working or looking for work. This means that more than half of all American homes do not have a full-time homemaker anymore.
Question : What is the main idea of this passage?

According to the author, what is the most important reason for the changes?