We propose a general framework for determining the extent of measurement error bias in ordinary least squares and instrumental variable (IV) estimators of linear models while allowing for measurement error in the validation source. We apply this method by validating Survey of Health, Ageing and Retirement in Europe data with Danish administrative registers. Contrary to most validation studies, we find that measurement error in income is classical once we account for imperfect validation data. We find nonclassical measurement error in schooling, causing a 38% amplification bias in IV estimators of the returns, with important implications for the program evaluation literature.

Conscription forces young men to serve in the military, irrespective of their opportunity costs. Using random assignment in the Danish draft lottery, we find a negative average effect of peacetime military service on earnings, an effect varying by ability, with high-ability men facing a $23,000 lifetime earnings penalty but with low-ability men facing none. This gradient is robust to different measures of labor market prospects. Educational disruption is an important mechanism, while service has little effect on health or criminal activity. The opportunity costs of conscription are borne by men with the best labor market prospects.

We model the correlations of brothers' earnings isolating the effect of fathers' earnings from additional residual influences shared between brothers. We separate the two effects by analysing sibling correlations and intergenerational correlations jointly within a unified framework. Our multi-person model of earnings dynamics distinguishes permanent from transitory shocks, allows for heterogeneous life cycle effects and nests previous models. Using data on the Danish population of father/first-son/second-son triplets, we corroborate the findings of studies that do not account for life cycle effects for those aged in their 30's, but find correlations twice as large at 25. The impact of intergenerational effects also varies over age, but is everywhere higher than found in previous studies ?by on average a factor of thirteen? and accounts for most of the sibling correlation. We provide evidence that lack of both life cycle effects and heterogeneous intergenerational transmission across families in previous studies explain the difference. When allowing for differential intergenerational transmission within families, we find mild evidence of stronger transmission to second sons.