At times, the redactor preserved his sources as he inherited them, at times, he mildly altered them, and, at times, he significantly shaped them. How to find the precise balance between the conservative and creative dimensions of this editorial process is still unclear, but today there is a broad consensus that the Mishnah should be viewed as a tightly edited composition (see Wald 2007a). Even if the editorial process may have been limited at times to the selection and arrangement of earlier materials, these editorial judgements are of major significance since they reflect the concerns and goals of the Mishnah’s redactor/anthologist. In short, the Mishnah is now viewed not merely as a conduit through which earlier tannaitic literary materials were preserved, but also as composition it its own right.
Amram Tropper, “The State of Mishnah Studies,” Rabbinic Texts and the History of Late-Roman Palestine, ed. Martin Goodman & Philip Alexander (Oxford: Oxford University Press, 2010), 103.