A World City vs. A Mega City

Not sure how you define a world city. It just seems that you know what they are. London, New York, Hong Kong. These are world cities. Seoul, Toronto, Chicago. Mega Cities and financial centres for sure, but world cities? I would argue not. Here's why:



1- There isn't necessarily a dominant culture-
Look at Hong Kong, many Chinese participate in non-Chinese things. The British pub has more Chinese than Brits. The owners were also Chinese. In a city like Seoul it is usually a foreign owned business (man marries local girl, opens bar) and the only locals are ones who have lived abroad extensively or want to (man marries local girl and takes her home). I would wager that the vast majority of Koreans have never been to Itaewon, and some would look down on those who did. In contrast Hong Kong is like London, where you have Chinese food one night, Filipino karaoke the next, pub dinner the next and Italian food the next. A city like Chicago has many foreign districts, but it is essentially an American city. Outside of Itaewon and Hongdae Seoul is firmly Korean. Hong Kong certainly in Chinese and London is certainly English, but also they are not (yeah, that makes sense). As an example the 9/11 attacks on New York was certainly an American tragedy, but look at how the world reacted, the shock and grief of people who had never been to the US was very real. Would that same reaction have occurred if the attacks had been in Chicago? Also, many cities and countries may not want this. Would Koreans ever want Seoul to not be 100% Korean? Would Chicago ever want to be anything but a huge American city?

2- They are diverse trendsetters globally-
Sports, art, movies, fashion, music, politics, technology, finance.
Now one may say that LA dominates the US (and global) film industry, but how many films and movies take place in New York? New York also dominates in sports, finance and art. London has sports, art, finance and fashion down, though probably not movies and TV outside the UK market. Hong Kong has finance, fashion, technology and arts down, not sure about sports. Seoul comes in here. Certainly in technology and Kpop has a strong following in Asia, but it is only one genre of music and one with little staying power at that. In fashion and sports it has made progress but I can't see Korean men's fashion ever catching on outside Korea, though women's fashion could. A city like Mumbai also dominates many of these fields, but it is still mostly confined to the Indian market. A city like Manchester may dominate in sports, but that is it. Toronto dominates Canadian sports and arts, but that is a tiny market indeed. Singapore rules SE Asian finance and arts, but what pull does that have globally?

3- They've been around.
I don't say that Seoul or Mumbai aren't world cities, they just aren't yet. New York has been a cultural icon since at least WWI, London much longer. Hong Kong and Tokyo are really since the 1960's but that is fifty years. Twenty years ago no one had heard of Seoul and Mumbai was still Bombay. Maybe this generation growing up with Samsung and Hyundai will give Seoul a place in that pantheon, but not yet.