Study (PIRLS) for fourth graders. Our analysis covers six European countries, Germany, France, Iceland, the Netherlands … analysis covers six European countries, Germany, France, Iceland, the Netherlands, Norway, and Sweden. Peer effects are of … school, which come about by chance. Hanushek et al. (2003) and McEwan (2003) also use within school variation to identify …

the question whether the omission of important control variables in matching estimation leads to biased impact estimates …