This review of recent research on the actual and perceived benefits and costs of children to their parents discusses the significance of such information to population policy makers and to parents. Conducted in developing countries (in Southeast Asia) and in the United States (with data primarily from Hawaii), the research demonstrates that the perceived costs and values of children affect birth rate and family planning behavior and that perceived economic dimensions appear to be of greater importance than socio-psychological ones. Parents in rural areas of developing countries tend to overestimate the potential economic contribution of children to the family, and parents in all countries greatly underestimate actual costs involved. An economic approach to reducing population growth is suggested. In less developed societies, this might be accomplished by developing social security systems for the aged (weakening the motive to have many children for old-age security), by substituting mothers' labor for that of children, and by simply providing parents with information on actual costs involved in childrearing. Tabular illustrations throughout the text include data on average U.S. costs for supporting a child from birth through college, with accompanying calculations for "lost" earnings of the non-working mother. (BF)