I was just looking up GDP for various cities in America and saw that the amount of economic activity in L.A. is almost as much as Chicago and Philadelphia, put together!

Now I know that GDP isn't the best gauge for the underworld BUT, I do think they go hand in hand.

NY $1,358,000,000,000
L.A. $765,000,000,000
Chicago $571,000,000,000
Philly $364,000,000,000