From interest rates to bond yields, how has Federal Reserve Chairwoman Janet Yellen’s first 18 months at the top post compared to her predecessor, Ben Bernanke? For one thing, they each oversaw very different economic climates. Photo: Getty Don’t miss a WSJ video, subscribe here: http://bit.ly/14Q81Xy More from the Wall Street Journal: Visit WSJ.com: http://www.wsj.com Visit the WSJ Video Center: https://wsj.com/video On Facebook: / videos On Twitter: / wsj On Snapchat: https://on.wsj.com/2ratjSM