What progressive reform most favored the leadership of experts to solve complex problems?

The progressive reform that most favored the leadership of experts was the establishment of the "scientific management" movement, particularly promoted by figures like Frederick Winslow Taylor. This approach emphasized efficiency and expertise in both industry and public administration, advocating for the application of scientific principles to improve organizational processes. Progressives believed that trained professionals and specialists could address complex social and economic issues more effectively than traditional political leaders or laypersons. This shift towards expert-driven governance laid the groundwork for the modern administrative state.