Using input and outcome data from a randomized study of dual-language immersion programs in an urban district, we examine the mediating relationships of dosage, expenditures, and classroom characteristics to students' academic performance, and the moderating role of students' race/ethnicity. Differential costs of immersion were concentrated at the…

Though it is estimated that about half of the world's population is bilingual, the estimate for the United States is well below 20% (Grosjean, 2010). Amid growing recognition of the need for second language skills to facilitate international commerce and national security and to enhance learning opportunities for non-native speakers of English,…