This study brings existing education finance literature and theory to bear on a comparatively understudied context: within-district funding. I review studies of education finance literature that use education production function frameworks to show the causal impact of education spending. The consensus of these studies' findings---that funding consistently contributes to improved student outcomes---shows that the ways we decide to direct education dollars represent critical policy choices. To that end, I discuss theories of equity in the provision of education, which form the basis of policies structured according to adequacy and horizontal and vertical equity principles. I then use longitudinal school-level spending data from New York City to analyze whether introducing a student-based funding formula, built on vertical equity principles, helped to improve fiscal equity for students in NYC schools with educational needs targeted under the formula. My findings suggest that the formula's partial implementation hindered its effectiveness at creating more fiscal equity for educationally disadvantaged students, but the new funding policy did dramatically raise per-pupil spending levels.