The Estimation of Unwanted Fertility: Development of A New Method John B. Casterline * and Laila O. El-Zeini ** 15 March 2006 * Professor of Sociology and Demography, Pennsylvania State University, University Park, Pennsylvania, 16802. jcasterline@pop.psu.edu ** Associate Professor, Department of Statistics, Cairo University and Social Research Center, American University in Cairo lelzeini@aucegypt.edu Paper for presentation at the annual meeting of the Population Association of America, Los Angeles, 30 March - 1 April 2006. This research is supported by grant R03 HD051697-01 from the National Institute of Child Health and Development. The paper has benefited from comments at seminars at the Ohio State University and the City University of New York.