Fetter notably debated Alfred Marshall, presenting a theoretical reassessment of land as capital. Fetter's arguments have been credited with prompting mainstream economists to abandon the Georgist idea "that land is a unique factor of production and hence that there is any special need for a special theory of ground rent..." A proponent of the subjective theory of value, Fetter emphasized the importance of time preference and rebuffed Irving Fisher for abandoning the pure time preference theory of interest that Fisher had earlier espoused in his 1907 book, "The Rate of Interest".