“…Note that duplicate subjects are not counted Freeman, 1970;Kapur, 1972;Tarsh, 1982;Crum and Parikh, 1983;Sear, 1983;Rudd, 1984;Montague and Odds, 1990;Johnes, 1992;Chapman, 1994;Rodgers and Ghosh, 2001;Smith and Naylor, 2001a;Bratti, 2002 Bee andDolton, 1985;Connolly and Smith, 1986 Age Age in 1993 Walker, 1975;Eaton and West, 1980;Smith and Naylor, 2001a Barnett and Lewis, 1963; Barnett et al, 1968;Kapur, 1972;Entwistle and Wilson, 1977;Bee andDolton, 1985 Nisbett andWelsh, 1972;Smith, 1990 Categorical explanatory variables: Rabash et al, 2004) in the MLM analysis.…”