Answer:
Despite the scarring in the U.S. national psyche, the economic effects of the 9/11 attacks were short-lived. While the local economies of the metropolitan areas of D.C. and New York were significantly hit, the size of the U.S. economy, the largest in the world, was back to trend in terms of GDP, the stock market, consumer confidence and the labor market within weeks.
As counterintuitive as this is, it highlights the sheer size of the U.S. economy, which at the time produced roughly 30 cents out of every dollar of world output – now about 25 cents out of every dollar. At a closer look, the Bureau of Labor Statistics cites finance, professional services, information, arts, entertainment, management and manufacturing industries as the hardest hit sectors of the New York economy due to the attacks.