In this paper we examine the diffusion of a syntactic change in a specialized text type in different World Englishes, in particular the use of be-passives in academic discourse in nine contact varieties of English and six ENL (i.e. native English) varieties. The Zurich-parsed International Corpus of English (ICE) makes it possible to retrieve automatically, for the first time, the two variants in the envelope of variation: active transitive constructions and be-passives. We apply a regression analysis in order to gauge the effect of potential external factors playing a role in the choice between them: regional variety (with potential influence from the substrate in the contact varieties) and academic sub-discipline. The use of the passive has undergone change in the twentieth century (see e.g. Leech et al., 2009). As a necessary backdrop for variation found in the ICE corpora, we therefore use historical data from the extended Brown family of corpora, which have also been parsed at the University of Zurich.
The results of our analysis show that regional variety is less important than academic sub-discipline: with the sole exception of American English, be-passives are similarly frequent in both ENL and contact varieties; moreover, they are distributed similarly across all varieties according to academic sub-discipline (humanities, social sciences, natural sciences and technology).