Americans are having fewer and fewer babies. It is now at a level at which the current generation can not exactly replace itself. Compared to their baby boomer parents, millennials and other young adults are simply not having many kids. But, why?

Since the Great Recession in 2007, the United States has seen a decline in fertility. At first, researchers thought a declining economy could've been the culprit but as the economy has recovered, the fertility rates have decreased.

In an effort to find the real cause of low fertility rates, a survey done by Morning Consult for The New York Times polled 1,858 respondents aged 20-45. They found that 64% of young adults said the main reason they aren't having a child is that child care is too expensive while 44% said they can't afford more children.

Why Young Adults Are Having Fewer Children Than Their Ideal Number

For the people who said they had or expected to have fewer children than they considered ideal, here's the share that cited each of these reasons as a factor.

Morning Consult Survey

This survey actually provides more insight into why adults are having fewer children. The average amount to raise a child through the age of 17 is now $233,610 (not including college). This estimate has skyrocketed 40% from 2000. To pay for a child, fours years or younger, would now amount to being $13,715.29 per year. It would actually be cheaper to send your child to an in-state college. Not to mention, young adults have a record amount of student debt. They say they'd like to pay off the debt and become financially stable before considering starting a family.

When the Great Recession hit in 2007, people's homes, jobs, and savings were taken with it. It came to an end in 2009, but the aftereffects can still be seen today. According to the study done by NY Times, 49% of young adults say they're too worried about another recession to have any more children.

Young people also say that they'd like to have more leisure time and personal freedom before embarking on parenthood. In a study done by Huffington Post, they found that American mother has, on average 36 minutes of leisure time a day. That's almost nothing. Most young adults would like to enjoy their youth.

Whether or not the younger generation will be able to "catch up" isn't certain, but it'll depend on their capacity to combine work and family.