The era of the aging worker is here. The forces driving the first decades of the 21st century -- globalization, technology, societal aging, and jarring economic instability -- have made later retirement a necessity for many, but those who choose to stay in the workforce are frustrated by a job market that fails to take advantage of their talents. As government's ability to finance retirement and health care declines, making space for older workers in the labor force has emerged as a chief challenge for the coming century. Veteran international correspondent Joseph Coleman spent three years...