The key to these papers is that younger
siblings spend fewer years with the departing parent before separation. Hence, the
use of sibling pairs potentially separates unmeasured family-specific characteristics
from the impact of fatherlessness or motherlessness. Both find that each additional
year of fatherlessness reduces the child's educational attainment. Grogger and Ronan
also find that fatherlessness reduces entry wages for whites and Hispanics but not
for blacks. While this approach is both creative and insightful, it inevitably cannot
be definitive. Within-family comparisons suffer from the risk that parental absence
may also affect the within family distribution of resources or that divorce affects
older and younger siblings differently.