1) In the late 19th/early 20th century, New York City solidified its economic dominance through industries like electricity, telephone, film, and radio. This allowed NYC to benefit greatly from postwar economic growth fueled by mass media and advertising. 2) While other cities like Moscow, Shanghai, Sao Paulo, and Dubai have grown rapidly in recent decades due to industries like manufacturing, energy, and technology, traditional global economic centers like New York, London, and Tokyo remain dominant economic powers. 3) As the world becomes increasingly urbanized and globalized, major cities are gaining influence and could emerge as new centers of global governance, with their large economies exceeding those of many nations.