Wonkblog economics editor Neil Irwin has a book coming out this week. “The Alchemists: Three Central Bankers and a World on Fire” (The Penguin Press, available April 4) tells the story of how central bankers came to exert vast influence over the global economy, and how they wielded that power from 2007 to 2012, through the financial crisis and its aftermath. Based on behind-the-scenes reporting that took place 27 cities in 11 countries, the book covers the global reach of the crisis through which the world is still living and puts it in its historical context.