Venture capitalist and anthropologist Stephen DeBerry says communities with little social, economic, and environmental advantages exist mainly on the east sides of cities and he has a theory as to why.

In his most recent Ted Talk, DeBerry uses the economic division between communities in East Palo Alto, California to explain what he sees as a larger trend in cities across the globe. According to DeBerry, the portions of East Palo Alto that lay on the west and east sides of the 101 freeway are a picture of inequality, with residents on the west side seeing advantages in areas like employment, housing and transportation, while residents on the east side experience the opposite.

DeBerry cites Detroit, Portland, Chicago, and a variety of other cities as examples of this east-west disparity. He says some of it is environmental, but that there are also man-made factors that contribute to this trend.

Watch DeBerry’s talk in full to hear his insights on why communities on the east sides of cities are at a disadvantage and what people can do to fix it.