The largest in the collection, this series is subdivided into four subseries: Research and Writings, Speeches and Lectures, Writings by Others, and Non-Academic Works. The most extensive subseries, Research and Writings subseries, contains a wealth of notes, data, subject files, and writings that underpinned and informed nearly all of Modigliani's most significant published works. These extensive files document the evolution of Modigliani's thought on a wide range of economic, social, and political topics, and the amount of material in this series contributed by his colleagues serves to underscore Modigliani's collaborative approach to research and writing.