Voice construction in academia is social, and involves weighing the complex interplay of various factors. This study explores the simultaneous influence of three social factors - disciplinary culture, writers' cultural background and rhetorical purpose - on writers' voice construction in writing research articles (RAs). Adopting a corpus-based approach and using Hyland's taxonomy of stance markers in analyzing RAs written by L1 and L2 writers in two disciplines, electrical engineering (EE) and applied linguistics (AL), results of quantitative analyses showed that disciplinary culture, among other factors, seems to play a dominant role in regulating academic writers' authorial presence. On the whole, writers in AL used stance markers much more frequently than writers in EE, while hedges occurred more than boosters in AL, but vice versa in EE. Also, the stance markers preferred by L1 and L2 writers were different. Finally, the high occurrence of boosters in conclusion sections of EE suggests a link between rhetorical purposes and authorial voice construction. An understanding of the various factors involved in voice construction could be of great pedagogical value since strategic management of self-representation conforming to disciplinary and general academic conventions could enhance the persuasiveness of RAs.