Her book, Mobilizing Zanzibari Women: The Struggle for Respectability and Self-Reliance in Colonial East Africa (Palgrave Macmillan, 2014), investigates Muslim girls’ education and women’s professionalization in twentieth-century Zanzibar. Her work also appears in Past & Present, the Journal of Women’s History, the International Journal of African Historical Studies, and Africa Today, as well as in edited volumes. She is co-authoring a book on the history of development in Africa with Elisabeth McMahon, now under contract with Cambridge University Press. Decker’s current research investigates the role of ethnography in debates about childhood sexuality in colonial East Africa.