To be fair, the women's butt swinging is Korean ripping off the american.
The logic is simple: the press says that more foreign women come to Korea to f*ck korean men, this means there should more be marriage/family and birthrate in S. Korea. Unfortunately, this isn't true, so unless the foreign women just use korean men as 1-night stand, I have doubt about the previous claim. And no, China and Japan have taken western hegemony of entertainment since at least the 60s with HK movies and samurai movies, and then 80s with japanese anime and chinese movies onward.
Also, I'd like source on either statement, please. I have provided mine, and I doubt that korean music can increase from less 1 billion USD to 12 billion USD in 3 years.