Methodological challenges in researching teacher supply: Implications for research, policies and practice

The lack of qualified teachers remains a major barrier to closing the attainment gap between rich and poor children. Policies relating to teacher supply and teacher effectiveness can play a critical role in overcoming disadvantage for millions of children living in poverty. Popular strategies to attract and retain teachers, used over several decades across the world, include bursaries, scholarships, performance related pay, professional development and reducing workload. Such policies have tended to be based on weak research evidence. Most previous studies do not consider the interactions of the different factors that can explain teacher shortages, and so give misleading results by focussing on a few factors only. Research to understand individuals’ choice of teaching as a career usually considers only those who are already in teaching or intending to teach, ignoring those who could potentially be teachers but chose not to. Such research is not helpful in informing policy and practice. Similarly, policies to improve the quality of teachers using value-added models are flawed, even damaging. Through a combination of data and designs, this chapter challenges conventional research in these areas and offers alternative explanations for teacher shortages, which will hopefully provide more informed evidence for policy decisions.