Migration could prevent a looming population crisis. But there are catches

Experts say migration could offset falling birth rates — if politics don't get in the way. (Didier Pallages/AFP via Getty Images)

To developmental economist Lant Pritchett, "population decline" is a mild way to describe what could be a global demographic crisis.

"The reaction is often 'ho-hum' as the rates [of population decline] are slow and hence the issue seems small and in the future," he told NPR in an email.