New York City may be the most densely populated metro area in the world, but its residents have a wide variety of cultures and experiences. In fact, NYC has an estimated 600+ languages spoken here, more than any other city in the US. This cultural diversity is reflected in the cuisine, music, and other aspects of life in NYC. For example, you can eat Mexican tacos for lunch and Chinese ramen for dinner in the same day. You can visit a large public garden for some natural beauty and fresh air, or head to a nightclub to listen to live music.

However, it’s important to note that the city is not a utopia; poverty still exists here in significant amounts. Especially in the outer boroughs, where there is often little public transportation. Many people here struggle with housing costs, and it is very common for low-income neighborhoods to be found on the east side of the city.

One theory for why this occurs is that it is related to past pollution. When cities began to grow quickly after the industrial revolution, many of the factories that were burning coal created a lot of smoke. Since prevailing winds in temperate zones tend to blow west, this meant that the smoke was carried away to eastern areas of the city. As a result, rich people moved to the west of the city and poor people lived in the east.

This same pattern is seen in many other cities. London, Paris, Berlin, Toronto and Manchester all have an “east side” that is poorer than the rest of the city. According to a study by Stephan Heblich, Alex Trew, and Yanos Zylberberg of the Spatial Economics Research Centre at the University of Bristol, this is because historical pollution caused neighborhood sorting that continues today.