Author Jonathan Last talks about his book, What to Expect When No One’s Expecting: America’s Coming Demographic Disaster, in which he discusses the population implosion in the U.S. and it’s impact on the economy, culture and politics. He argued that if the U.S. wants to continue to be a world leader, Americans must have more children. He discussed the country’s demographic changes with Pew Research Center’s D’Vera Cohn.