NBER Working Paper Series: Global Wealth Inequality , Gabriel Zucman, Working Paper 25462, January 2019. “This article reviews the recent literature on the dynamics of global wealth inequality. I first reconcile available estimates of wealth inequality in the United States. Both surveys and tax data show that wealth inequality has increased dramatically since the 1980s, with a top 1% wealth share around 40% in 2016 vs. 25–30% in the 1980s. Second, I discuss the fast growing literature on wealth inequality across the world. Evidence points towards a rise in global wealth concentration: for China, Europe, and the United States combined, the top 1% wealth share has increased from 28% in 1980 to 33% today, while the bottom 75% share hovered around 10%. Recent studies, however, may under-estimate the level and rise of inequality, as financial globalization makes it increasingly hard to measure wealth at the top. I discuss how new data sources (leaks from financial institutions, tax amnesties, and macroeconomic statistics of tax havens) can be leveraged to better capture the wealth of the rich.”

See also – “The World Inequality Database (WID.world) aims to provide open and convenient access to the most extensive available database on the historical evolution of the world distribution of income and wealth, both within countries and between countries.”