Should-Read: Nick Bunker: Equity, efficiency and education spending in the United States: "Released today as part of the Equitable Growth Working Paper series... Rucker C. Johnson of the University of California-Berkeley and C. Kirabo Jackson... http://equitablegrowth.org/equitablog/value-added/equity-efficiency-and-education-spending-in-the-united-states/
...find that there are complementarities.... This complementarity result may partially explain some of the fade-out for pre-kindergarten programs. It’s hard to maintain the gains from Head Start if the primary and secondary schools the child attends next aren’t well funded. But beyond the specific policy result, the paper also offers an illustration where the trade-off between equity and efficiency doesn’t seem to exist...