Author and Wharton Professor Jeremy Siegel says he expects the stock market to remain volatile, but says he thinks stocks are offering “extraordinary” long-term values. Siegel tells CNBC that stocks are “the asset class to be in” given those values, which are setting stocks up for “a very good decade … in fact, a very good three- to five-year period.” He’s particularly high on dividend stocks. Siegel also discusses the European debt crisis, and what he thinks the European Central Bank should do to help the situation.