Table 6

Results of the 2SLS Regression Explaining Birth Weight in ALSPAC

(1)(2)(3)(4)
#Cigarettes smoked per day−36.7+−37.9+
(21.1)(21.7)
#Cigarettes smoked per day (adjusted)−36.5+−38.5
(21.4)(23.9)
Control variablesNoYesNoYes
Effective F-statistic25.327.215.615.1
N7,5987,5983,7843,784
  • Notes: Coefficients are displayed with robust standard errors in parentheses. All regressions correct for genetic relatedness among the mothers using the first four principal components of the genetic relationship matrix. +p < 0.1, *p < 0.05, **p < 0.01.