<div>Lawrence R. Klein, who won the Nobel Prize in economics in 1980, is Benjamin Franklin Professor of Economics Emeritus at the University of Pennsylvania. Among his many books is <i>The Economics of Supply and Demand.</i> Marshall Pomer is President of the Macroeconomic Policy Institute, Santa Cruz, California. He is the author of <i>Intergenerational Occupational Mobility in the United States: A Segmentation Perspective.</i></div>