This paper presents arguments for subsidizing developmental day care (preschool intervention) programs, which have as their goal helping children function competently in society and which include some types of assistance to the children's families. The growing need for day care and the inability of many families to pay for it, both in Texas and in the rest of the country, are pointed out. An extensive review of research identifies benefits to participating children and families, commonalities among effective preschool programs, and monetary savings or revenues generated by such programs which offset the costs of day care. The topics of research examined include the likelihood of harmful effects from out-of-home care; the intellect of children in day care, school performance, socialization, and health; family benefits; community changes, program specific factors, and economic factors. An analysis of the research reveals that young children who participate in developmental day care can develop as competently as their home-reared peers. In addition, programs with the intervention potential of developmental day care can result in substantial monetary savings and in fact generate revenue. The implications discussed include the social reality and necessity of day care, the need for more unity and organization in the provision of day care, the program characteristics important to effective day care, and the need for more subsidized day care for low-income families. It is concluded that developmental day care is cost effective, beneficial to children and families, and necessary. (Author/JA)