Aphorisms that “rising tides raise all boats” or that material advances of the rich eventually “trickle down” to the poor are really maxims regarding the nature of stochastic processes that underlay the income/wellbeing paths of groups of individuals. This paper looks at the implications...

1. Measuring the Wellbeing of Groups -- 2. Statistical Matters -- 3. Complete Orderings: Index Types and the Ambiguity Problem -- 4. Partial Orderings -- 5. Comparing Latent Subgroups -- 6. Ambiguity Comparability Segmentation and All That -- 7. Some Applications