Today’s Mail Online features a photo essay about housing for the urban poor in Hong Kong (the image here is from the story). The story draws attention to the often neglected inequality that marks very wealthy cities. One of the primary ways this inequality is expressed is through housing conditions and cost. As urban economies heat up, land prices rise and the urban working class is forced into long commutes between home and work and, as these pictures show, overcrowded and often dilapidated housing. While some observers blame the global urban housing crisis on mismanagement and offer mild policy correctives, as Engels observed in the 19th century the immiseration of the urban poor is not an unfortunate by product of urban prosperity, but its precondition.