There's a lot of conjecture regarding the most expensive city on earth. Many studies have been done, and lots of data has been collected, but nobody can seem to agree. 

The #1 ranking is really a relative status, based on exactly what variables of cost are taken into consideration.

But here is one undeniable fact: Fifth Avenue on Manhattan's Upper East Side is the most expensive retail market in the known universe.  

Fifth Avenue on UES is 50% more expensive than the second priciest area in the world: Hong Kong's main street and shopping district, Causeway Bay.

The rent on Fifth Avenue between 49th and 60th Street rose 3.6% since last year, landing at $3,500 per square foot. Obviously, for the cost of one square foot of UES property, one could rent a really nice apartment elsewhere in New York City, or anywhere on Earth for that matter.

Across the Pacific, rates in Causeway Bay are a whopping 46% below that of Manhattan's uber-desirable UES, weighing in at $2,399 per square foot.

Remember, these rates are not the total rent for the units. These rates are for one square foot of space. One.

via The Real Deal

Similar to Hong Kong's Causeway Bay, the area of UES that has the priciest per square foot rates retains its pinnacle status with support from a booming tourism industry filling the retail locations in around the neighborhood.

The margin between Manhattan's UES, Hong Kong's Causeway Bay, and every other place on the list is pretty wide. Properties on Paris' Avenue des Champs Elysees, perhaps one of the most famous avenues in the world, only demand $1,372 per square foot. 

That makes Manhattan's most desirable real estate two and a half times costlier than one of the most well-known avenues in the world.

It's no surprise, really. We're the most expensive City in the world.

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