We treat each age-specific income-earning member of the family as an income “source,” and use the source-specific Gini decomposition approach as well as the Lorenz comparison approach to study the impact of the changing population age structure on family income inequality. Empirical analysis using Taiwanese data shows that the pattern of Gini coefficients is significantly affected by the above-mentioned age composition factor. The general implication is that for many developing countries which have recently gone through rapid demographic transition, family income inequality indexed may implicitly embody information as to the age-specific composition of family members, which is irrelevant to the general notion of inequality.

This paper uses three different approaches to investigate whether the declining provision of public capital is a major cause of declining labor productivity. The juxtaposition of approaches removes the variability in estimates due to dissimilar variable definitions and econometric methodologies. Estimates are based on U.S. time-series data and are evaluated by the implied elasticities of substitution, the prediction of labor productivity trends, and the impact of public capital on productivity. As the three approaches yield very different estimates, it will be hard to ever settle the debate about the effect of public capital on private productivity.