The U.S. labor force is expected to expand only slowly over the coming decade as the country ages and more Americans give up on holding a job, a potential drag on broader economic growth. The economy is expected to generate 9.8 million new jobs, a 6.5% increase, from 2014 to 2024, the Labor Department said in new projections released Tuesday. While steady, that is a historically slow pace. By comparison, 10-year job creation averaged almost 14% during the 2001-07 expansion and close to 17% during the 1990s. The slowdown highlights declining participation as baby boomers retire and younger Americans opt...