The 2020 U.S. presidential election may be a year away but one policy idea is already stirring fierce debate: a big-time tax on the richest Americans. Katia Dmitrieva reports on why Bernie Sanders and Elizabeth Warren want to implement a wealth tax, and how it might work. Many economists have also been warming to the idea of taxing wealth. But you can't help noticing that most of the European countries that have tried wealth taxes have later junked them. Host Stephanie Flanders talks with Bloomberg economists Johanna Jeansson and Maeva Cousin about the death of wealth taxes in Sweden and France and the possible lessons for the US.  Then Stephanie talks with Frankfurt-based economy editor Jana Randow about two major milestones in the region: Christine Lagarde taking over as president of the European Central Bank and the 30th anniversary of the fall of the Berlin Wall. Randow -- the co-author of a recent book about outgoing ECB head Mario Draghi -- explains how Lagarde is likely to differ from her predecessor. She then shares her personal memories of November 1989 from the standpoint of a child growing up in East Germany.