*my > (*ny) in Greek and Italic: Common innovation, parallel development, or fortuitous similarity?

The fact that the final -m of PIE *gwem- is reflected as -n in Greek baino, Latin uenio, and related forms has given rise to a number of different accounts, the most common of which explains the n as the result of some kind of assimilation. I review the various proposed accounts and argue that similarity between Greek and Latin n is accidental. The Latin n results from analogical extension of the third singular root aorist form, in which -n results from sound change. The Greek n reflects regular sound changes connected with across-the-board palatalization in that language.