One factor probably affecting the decision to have children is the amount of money you think is needed.
This recent report on research about the amount you need to be happy may give some clues.
"On average, survey respondents said they would need $1.2 million in the bank and a salary of $284,167 per year to be happy. But averages can conceal major differences among respondent groups. Here are the actual results broken out by each generation:
Generation Z: Annual income of $128,000, net worth of $487,711
Millennials: Annual income of $525,000, net worth of $1,699,571
Generation X: Annual income of $130,000, net worth of $1,213,759
Boomers: Annual income of $124,000, net worth of $999,945."