The American tax system is sometimes called progressive, and it operates very differently for the ultra-wealthy. This week on Mountain Money, Boston College tax law professor Ray Madoff joins the show to talk about her new book, The Second Estate: How the Tax Code Made an American Aristocracy. She explains how the richest Americans can legally opt out of traditional income and estate taxes, the mechanics of the "buy, borrow, die" strategy, and how current rules shift the country's tax burden onto everyday wage earners.