Well not quite worthless:
...the United States gives less money per capita than any other member nation. The U.S. share of the United Nations regular budget for 1999 was $298 million. This is the equivalent of $1.11 per citizen. The tiny island of San Marino pays $4.26 per citizen.
Additionally, the United Nations creates more money for U.S. companies and cities than the amount the U.S. government pays to the United Nations. The United Nations contributes $3.2 billion a year to the economy of New York City alone. Of the goods and services purchased by the United Nations system in 1997, U.S. companies received $404 million. United States citizens hold more United Nations staff jobs than any other country.
No doubt sending UN headquarters to Ghana or Germany would be a real economic boon to them.
The head of the state's UNDC, Roy Goodman, the former senator, notes that the U.N. is worth $2.5 billion a year to the city's economy - not counting the construction jobs that go with the proposed expansion. These are tempting arguments, but it is an analysis that is typically static. Mr. Goodman ignores the prospect that private enterprise making use of the same land on market terms could do more for the city than the United Nations. It's hard to see how it could do worse.