The population projections offer a glimpse of what the nation may look like at the turn of the next century, though a forecast decades into the future can't predict the unexpected like a global pandemic. The projections can help the U.S. prepare for change, from anticipating the demands of health care for seniors to providing insight into the number of schools that need to be built over the coming decades, said Paul Ong, a public affairs professor at UCLA. “As most demographers realize, population projection is not an inevitable destiny, just a glimpse into a possible future,” Ong said.