An asymmetry between VO and OV languages

The World Atlas of Language Structures has established an interesting asymmetry between head-initial (VO) and head-final (OV) languages with respect to the ordering of oblique phrases, i.e., phrases corresponding to with the key and on the table in opened [the door] [with the key] and put [the book] [on the table]. Head-initial grammars have a consistent and almost exceptionless preference for VOX order. Head-final grammars have variable basic orders: all of XOV, OXV and OVX are productively attested, and there are fewer clear basic orders than in VO languages. In this paper I offer a multi-factor explanation for this grammatical asymmetry in terms of processing efficiency, developing principles proposed in Hawkins (1994, 2004).