After delivering an extraordinary 32% return in 2013, the U.S. stock market has had a shaky start in the new year. But in an interview with Knowledge at Wharton, Wharton finance professor Jeremy Siegel says corporate earnings are strong, and the U.S. economy is likely to grow at a healthy rate in 2014. According to Siegel, stocks are not overpriced relative to earnings, but bonds are a risky play as interest rates rise. An edited transcript of the conversation appears below. Knowledge at Wharton : It’s late January, and everybody’s getting their year-end statements from 2013 and seeing the stupendous gains they made in the stock market, and they are getting ready to pay taxes on them. And now, all of a sudden, we seem to be falling off a cliff. The S&P 500 is down about 3% year-to-date, after being up 32% last year. What is going on? Siegel : It shows you how used to gains we are. After being up 32%, we call being down 3% “off a cliff.” I regard it as a little bump.…