It has been happening since immigrants from Europe began pouring into the city in their millions in the last century and it continues today as New York keeps its doors open to all-comers. While European countries do all they can to keep foreigners out, New York encourages them with open arms, down to providing an amnesty for those who slip into the country illegally.
For the unwary, however, the welcome mat can be as treacherous as a banana skin.
On arriving here seven years ago, having driven across the country from California, I was the victim of three robberies in the space of a few weeks. The first two were by common thieves, the third occurred in broad daylight when a sharply attired apartment broker walked off with a hefty commission and handed me the keys to a shoebox-sized flat.
Involuntarily relieved of my trusty Chevy Malibu, and with a considerably lighter wallet, I was assured that this was the best way to start out in New York. I was consoled by native New Yorkers who said that driving in the city is impossible anyway, and being robbed with a fountain pen is a better option than being mugged at knifepoint.
Once through the initial acclimatisation process, the city never fails to delight, astonish or appal. Its architecture is striking and overwhelming at its best, and miserable and decrepit at its worst - and all too often the two are side by side.
The elegant art nouveau Chrysler Building, with its motifs of chrome and steel inspired by the American automobile, dominates the city's East Side, though it is by no means the biggest or most grandiose building around. Next door is Grand Central Station, where shafts of sunlight enter through cathedral-like windows to illuminate the hurrying masses of people in the main concourse. It has been the backdrop for a thousand movies and it remains one of the most striking places in the city.
What ultimately makes Manhattan so attractive, however, is that it is lived in and that each neighbourhood has its own special character and energy. Walk out of an apartment building, and the city assaults the senses. From the honking yellow cabs, driven by immigrants with barely a word of English and even less knowledge of the geography of the city, to the homeless people who take up residence over a hot steam vent.
There is no way of being indifferent about New York. It either thrills and excites, or it depresses and annoys - and it requires people to be on their guard at all times. New Yorkers themselves are pushy and rude, knowing that if they are not, they will be left behind or left out. By the same token, the city attracts talented and interesting people from around the world, making it a place where social gatherings become an art form.
Helping to ensure that the pulse of the naked city is always brisk, are the city's tabloids which breathlessly chronicle each and every scandal while ceaselessly exposing municipal corruption. The tabloids build up such larger-than-life characters as Leona Helmsley, the tax- dodging hotel queen, and Donald Trump, the casino owner and developer, only to tear them down and, worst of all, ignore them, when it feels they have been sufficiently discredited in the public eye.
New York is also a city where people are allowed to remake themselves in whatever way they chose. Money and talent are the keys to success, not social class or bloodlines. And for those that came here because they felt downtrodden at home, be they oppressed minorities or homosexuals, the city takes them all as equals and allows them to celebrate their differences in a way that is quite unique.
The schools chancellor recently suspended a local school board in Queens because it refused to apply the official multicultural curriculum, which puts special emphasis on tolerance for gays and encourages teachers to promote other cultural models than Western European.
Hopelessly bureaucratic and chaotic, the city government acts as if it was running a minor state, complete with its own controversial foreign policy positions on issues from Haiti to Israel to Northern Ireland, each reflecting the politics of a particular vested interest. And every day the city seems to define itself through a new crisis, be it crime, drugs, Aids or bigotry and racism.
Spending such a roller- coaster period here as a visitor could not end without some further controversy. This time it was provided by the moving company, who decided to seal up the truck and leave before they had finished the job. My New York neighbours were delighted to pick through the tables and chairs and other furnishings left behind by the movers. New York is fun, but it's also a racket.