 One of his first works, co-authoring "Geography of the World's Agriculture" (1917) with Vernor Clifford Finch, led him to even wider recognition.Shortly after its publication, Baker returned to the University of Wisconsin–Madison for further graduate study, in economics, and earned his Ph.D. in 1921 with a dissertation on land utilization.While there, Baker had been influenced by Henry Charles Taylor and Richard T. Ely, two notable economists, to shift his work more toward the economic aspect of geography and agriculture.