This is the companion data for ACEnucfam.
data(mfblong)The data is a random subset of the birth weight data from the mental health registry of Norway.
male-a dummy variable for being male; first-a dummy variable for being the first child; midage-a dummy variable for mother aged 20-35 at time of birth; highage-a dummy variable for mother older than 35 at time of birth and birthyr-year of birth minus 1967 (earliest birth year in birth registry).
Rabe-Hesketh S, Skrondal A, Gjessing HK. Biometrical modeling of twin and family data using standard mixed model software. Biometrics 2008, 64:280-288