Why did the size of the U.S. economy increase by 3 percent on one day in mid-2013—or Ghana’s balloon by 60 percent overnight in 2010? Why did the U.K. financial industry show its fastest expansion ever at the end of 2008—just as the world’s financial system went into meltdown? And why...

Why did the size of the U.S. economy increase by 3 percent on one day in mid-2013—or Ghana’s balloon by 60 percent overnight in 2010? Why did the U.K. financial industry show its fastest expansion ever at the end of 2008—just as the world’s financial system went into meltdown? And why...