Horizontal and vertical measures of inequality are related through mobility. The paper draws attention to two types of mobility: quantity mobility, which refers to mobility in income itself, and rank mobility, which refers to mobility in the position in the distribution of income. Individually...

An econometric methodology is developed for nonparametric estimation of concave production technologies. The methodology, based on the principle of maximum likelihood, uses entropic distance and convex programming techniques to estimate production functions. Empirical applications are presented...

Empirical tests of APT have relied on factor analysis to estimate the risk factors. Here the authors propose a diff erent two-stage iterative methodology that relates risk factors to ex plicit economic variables. In the first stage, portfolio returns are regressed over time against these...