Chart of the day: Krugman's most important chart

Business Insider does an occasional series of interviews with important people from the world of finance, where they ask them what the most important chart in the world is. For Paul Krugman, it is the bond yields of Spain. He told Joe Weisenthal:

It's the first chart he looks at every day when he wakes up, as it's one of the key gauges for Euro crisis risk.