Much of his work has concentrated on the historical conception of monotheism in ancient Israel and the Hebrew Bible.
Through major research projects, publications, conference organization, and editorial undertakings, his academic endeavors have helped bridge Anglo-American and Continental biblical scholarship.
Overlapping with his time as reader at St Andrews and then lecturer and fellow in Cambridge, MacDonald directed the Sofia Kovalevskaya research project "Early Jewish Monotheisms" from 2009–14, hosted by Hermann Spieckermann in the Faculty of Theology at the University of Göttingen.
[2] He has also conducted his research during stays at Ludwig Maximilian University of Munich and the Kenyon Institute, in Jerusalem.
"[16][17] He also edits the sub-series "Studies of the Sofja Kovalevskaja Research Group on Early Jewish Monotheisms," which comprises part of Mohr Siebeck's book series Forschungen zum alten Testament.