Whence the Austronesian indirect possession construction?

Possession in some Austronesian languages shows levels of elaboration far in excess of cross-linguistic norms, while in others it is strikingly unelaborated. The appearance of alienable/inalienable contrasts has been assumed to result from contact with Papuan languages, and the existence of a paradigm of indirect possessive classifiers is cited as one of the pieces of evidence for the Oceanic subgroup, while acknowledging that indirect possession constructions can be found in Malayo-Polynesian languages further west. We argue that the appearance of possessive classifiers in these languages is also the result of contact with Papuan languages west of New Guinea.