This paper examines the flow of teachers between schools of different socio-economic statuses. New Zealand Ministry of Education data is examined with regard to teacher age and salary structures in schools from high and low socio-economic intakes. Teacher mobility data is examined and a model of the mobility life cycle of a 'typical' teacher reveals causes of the staffing discrepancies between schools with differing socio-economic intakes. The model accounts for the tendency for low socio-economic intake schools to have staff who are older and at lower salary levels than those from high socio-economic intake schools A theoretical interpretation of the situation in New Zealand is provided. It is argued that there is competition between schools for teachers' labour, and this has had the effect of exacerbating the social stratification flowing from market oriented reforms promoting consumer choice in New Zealand education.