index values between 1990 and 2008, they find that those countries that increased levels of inequality experienced slower annual per capita GDP growth over the same time period. Noting a lack of data for national wealth, they build an index using Forbes list of billionaires by country normalized by GDP and validated through correlation with a Gini coefficient for wealth and the share of wealth going to the top decile. They find that many countries generating low rates of economic growth are also characterized by a high level of wealth inequality with wealth concentration among a class of entrenched elites. They conclude that extreme inequality in the distribution of wealth globally, regionally and nationally, coupled with the negative effects of higher levels of income disparities, should make us question current economic development approaches and examine the need to place equity at the center of the development agenda. Ostry, et al. (2014) reject the hypothesis that there is a major trade-off between a reduction of income inequality (through income redistribution) and economic growth. If that were the case, they hold, then redistribution that reduces income inequality would on average be bad for growth, taking into account both the direct effect of higher redistribution and the effect of the resulting lower inequality. Their research shows rather the opposite: increasing income inequality always has a significant and, in most cases, negative effect on economic growth while redistribution has an overall pro-growth effect (in one sample) or no growth effect. Their conclusion is that increasing inequality, particularly when inequality is already high, results in low growth, if any, and such growth may be unsustainable over long periods. Piketty and Saez (2014) note that there are important differences between income and wealth inequality dynamics. First, wealth concentration is always much higher than income concentration. The top 10 percent of wealth share typically falls in the 60 to 90 percent range of all wealth, whereas the top 10 percent income share is in the 30 to 50 percent range. The bottom 50 percent wealth share is always less than 5 percent, whereas the bottom 50 percent income share generally falls in the 20 to 30 percent range. The bottom half of the population hardly owns any wealth, but it does earn appreciable income:The inequality of labor income can be high, but it is usually much less extreme. On average, members of the bottom half of the