With a mix of mandatory public and private pension programs, the Netherlands has the world’s best retirement system, according to a new ranking from the consulting firm Mercer. The European nation earned top marks among the 47 retirement systems included in the annual survey, sharing an “A” grade with Iceland, Denmark and Israel, each of which provides a “first-class and robust retirement income system that delivers good benefits, is sustainable and has a high level of integrity.” The U.S., on t