School district revenues per student differ significantly throughout the state. For instance, per student revenue-including all local, state, and federal aid-in 1995-96 (the most recent data available) among California unified school districts ranged from $4,042 to $12,528 per student, with an average of $5,160. No single funding source is responsible for the significant differences in revenue among districts. In part, the differences reflect additional funds available to districts that serve low-income students with specific needs. Funding differences also stem from historical and local economic factors. We explain in more detail below the magnitude of revenue differences among districts and some of the reasons for the gaps.