Are smartphones causing people to have fewer children? A provocative new working paper explores the persistent drop in birth rates since the iPhone was introduced nearly two decades ago.

WASHINGTON — As governments around the world struggle with ways to reverse plunging birth rates, new US studies suggest they have ignored a key culprit -- the smartphone.

As governments around the world struggle with ways to reverse plunging birth rates, new US studies suggest they have ignored a key culprit the smartphone.