pSouth Korea is cool. Even Barack Obama has acknowledged it. In the space of just a few decades, it's gone from one of the poorest countries to one of the world's richest. At the same time, a wave of Korean culture is washing over the globe. Japanese teenagers listen to K-Pop and families from Iran to Cuba watch Korean soap operas on television. What's the link between a booming economy and pop culture? Markus Karlsson asks Euny Hong, author of "The Birth of Korean Cool".