Bonjour, Dorothe; Cherkas, Lynn; Haskel, Jonathan; … - C.E.P.R. Discussion Papers - 2002
in three areas. First, we use identical twins, to control for family effects and genetic ability bias, and the education … findings suggest lower ability bias in within-twin pair regressions than pooled regressions. Third, using data on twins smoking … we show smoking reflects family background and using it as an instrument exacerbates ability bias. …