Here are a couple of related dissertations:

Mahboob, A. (2003). Status of nonnative English speakers as ESL teachers in the United States. (Order No. 3094117, Indiana University). Proquest Dissertations and Theses, Retrieved from http://search.proquest.com/docview/305332597?accountid=28598.(305332597)

Reis, D. S. (2010). Non-native English-speaking teachers and professional legitimacy: A sociocultural theoretical perspective on identity realization. ProQuest Dissertations and Theses, Retrieved from http://search.proquest.com.proxy.seattleu.edu/pqrl/docview/217742439/84BBADDB3B68409DPQ/2?accountid=28598