While roughly 2.12 babies were born per adult woman prior to the recession in 2007, people are now expected to have no more than 1.9 babies per woman for the next five years—not enough to replenish the population base, according to data analysis company Demographic Intelligence. Ideally, 2.1 babies would be born per woman, according to the Wall Street Journal.

A failure of birth rates to rebound could result in permanent changes in the economy. Toy stores such as Toys “R” Us have already reported dampening sales after birth rates fell following the financial crisis. Hospitals are also making changes to their maternity wards in response, and sales of single-family homes are hitting a lull as millennials are waiting until later in their lives to settle down, have children, and buy a home.

Japan’s demographic crisis, where the birth rates have fallen to 1.4 children per woman, is an extreme example of where developed countries could be headed. The nation’s growing elderly population is beginning to experience a shortage in nurses, while medical and pension costs are expected to balloon. Japanese companies, anticipating a smaller consumer base, have invested less in capital spending, while real wage growth has stagnated.

A shrinking workforce and consumer population in the U.S. could mean a smaller GDP, as well as fewer paying into social security and Medicaid in the long-term. Shifts in where and how many babies are born in a state can also cause imbalances in electoral power later down the line.

The source of the problem in the U.S. is varied according to the Journal, including fewer Latino immigrants coming to the U.S., women focusing on their careers rather than childbearing, and the weaker job market and economy. The Journal also noted that young adults today are not as close with organized religion as their parents, a group that has traditionally had more children.