This report presents the fourth study conducted by the Massachusetts Early Childhood Advisory Council since its inception in 1985, an investigation focusing on how interagency collaboration occurs in local early childhood programs in Massachusetts and whether mandating interagency councils is effective in promoting collaboration. The report also examines philosophical issues related to collaboration through a review of extant research. Based partially on the findings of surveys examining the degree and quality of interagency collaboration, six communities were selected for in-depth study using ethnographic methods. Teams of two interviewers visited each site, interviewing individuals involved in the collaborative effort and attending advisory council meetings. Each team compiled a report and met with the Future Trends Subcommittee to examine findings. The case studies in this report characterize the cultures of the six communities as bureaucratic, entrepreneurial, communal, or paternalistic. Understanding the culture of each community was critical in leading the Council to the conclusion that there are several ways for communities to collaborate. Findings indicate that interagency collaboration helps children and families, increases community involvement in schools, leads to a coordinated system of service delivery, leads to improvement in the quality of services, and is efficient and cost effective. Based on the information from the study and a review of recent literature, the Massachusetts Early Childhood Advisory Council recommended four strategies for policymakers and organizational leaders in fostering interagency collaboration: (1) consider the culture; (2) create a climate for collaboration; (3) involve a broad constituency; and (4) support collaborative efforts. The report's four appendices describe the study methodology, contain a checklist summarizing the factors found to facilitate long-term collaborative relationships, present a sample survey, and summarize information on the impact of budget cuts for local agencies. (Contains 34 references.) (KB)