THE AMERICAN GHETTO: A HUMAN EXPERIMENTCities have been the sites for some of the world's most squalid conditions; yet, they are also where reformers have been most innovative. In recent years, the United States has seen some creative experimentation in tackling the most intractable of all urban dilemmas: the ghetto. We have asked some leading figures to reflect on the American experience and put it into global perspective. Chaired by Guangyao Jin, Fudan University, with Mitchell Duneier, Princeton University; Douglas Massey, Princeton University; and Mario Luis Small, University of Chicago.