Research has shown that well-designed early education programs serving disadvantaged children in the year or so prior to kindergarten entry can generate benefits to government and the rest of society that outweigh the costs of the program services. As a result of this evidence and the conviction that children benefit from structured programs preparing them for school entry, enthusiasm for public-sector investment in preschool education has been growing among business leaders, policymakers, and the public. Within this context, there is growing interest in universal preschool education in California. In considering such a program, policymakers and the public focus on the potential benefits from a universal preschool program, as well as the estimated costs. This study aims to inform such deliberations by conducting an analysis of the economic returns from investing in preschool education in California. Appended are: (1) Methodology and Sources for Benefit-Cost Analysis; (2) Methods and Sources for Estimating Measured Preschool Benefits; (3) Methods and Sources for Estimating Projected Preschools Benefits; (4) Benefit-Cost Estimates for a Targeted Preschool Program; (5) No Preschool Baseline; and (6) Current Preschool Participation Baseline. (Contains 34 tables and 7 figures.)