“…The parameter β is of interest, see, e.g., Barro (2000). Besides the effect of income inequality on economic growth, this model is similarly applied to analyze the effect of inequality on consumption, investment, migration, and health, see, e.g., Atkinson and Brandolini (2001), Alesina and Angeletos (2005) and Jin et al (2011). In all of these studies, the population Gini coefficient is unknown, so empirical researchers have to work with the sample Gini coefficient denoted asα i , which is an estimator for the population Gini α i in the ith group.…”