This paper considers the effect of how children pass time before entrance to school on attainment in primary school. We find in National Child Developement Study data that Children perform marginally better at 7 and 11 if they spent time with their mother, or at a prre-school, rather than in...

With diminishing returns to the peer group, it is optimal social policy to mix children in schools. We consider what happens when, contrary to the outcome being determined by a social planner, schools and children are free to seek each other out: with some caveats, this leads to perfect...