On the upper West Side of New York City, a house divided by income

Even as so many crises roiled the world recently, the news that a development on the Upper West Side of Manhattan would proceed with a brand of distasteful social engineering still managed to command international attention. The building, in what is known as Riverside South, a stretch of land reaching below 72nd Street that seems largely like a pop-up location for people who have never heard of Katz’s deli or the G train, had received approval from the city for separate entrances — one for wealthy residents and one for those earning far less who would occupy the project’s affordable units, in a separate wing.