Teachers can shape their students' educational careers. Research shows that children taught by different teachers often experience very different educational outcomes. This begs the questions: how are teachers assigned to schools in different countries? And to what extent do students from different backgrounds have access to good teachers? Building on literature identifying the characteristics and practices of teaching that boost student achievement, this report shows how teachers with different characteristics and practices tend to concentrate in different schools, and how much access students with different socio-economic backgrounds have to good teachers. It points out the aspects of different educational systems that influence how teachers are allocated to schools. The report also discusses the consequences that inequitable teacher allocation systems have on students' educational outcomes.