A study was conducted on the factors which influence young women to marry or have their first child at a given age. The data used were taken from the National Longitudinal Survey of Young Women conducted by the Center for Human Resource Research at Ohio State University, during which a sample of 5,159 young women aged 14 to 24 in 1968 were interviewed yearly between 1968 and 1973. It was found that taste for market work, school enrollment, and mother's education all decrease the likelihood of a first marriage or birth at a given age. Young women in the South and those in rural areas are likely to marry and have their first child earlier than those in other regions or in urban areas. Black women are less likely to marry at almost any age than are white. The analysis showed that while in early adulthood current employment status has a small positive impact on the likelihood of a first marriage or birth at most ages, those variables which indicate a preference or preparation for future employment cause postponement of family formation. The analysis also provided evidence that the current trends in timing of family formation, women's educational attainment, and labor force participation are linked to a rise in general level of preference for market work among young women. (Tables of data and a list of references are appended.) (LMS)