I take a new approach to measuring world inequality and welfare over time by constructing robust bounds for these series instead of imposing parametric assumptions to compute point estimates. I derive sharp bounds on the Atkinson inequality index that are valid for any underlying distribution of...

We study a consumer non-sequential search oligopoly model with search cost heterogeneity. We first prove that an equilibrium in mixed strategies always exists. We then examine the nonparametric identification and estimation of the costs of search. We find that the sequence of points on the...