Alan Greenspan, who died Monday at the age of 100 , presided over a two-decade-long period of almost unprecedented American boom and economic dominance that’s now inaptly called “The Great Moderation.”  His long tenure as chairman of the Federal Reserve Board offers invaluable economic lessons that today’s Fed would be wise to heed. President Ronald Reagan nominated Greenspan as Fed chair in 1987, during his second White House term.  There Greenspan remained until 2006, reappointed by President