The World Wealth and Income Database (WID.world), co-directed by Facundo Alvaredo, Lucas Chancel and Thomas Piketty at the Paris School of Economics and Emanuel Saez and Gabriel Zucman at the University of California at Berkeley, provides high quality, fully public access to comprehensive and reliable data on income and wealth inequality. Surprisingly easy to use, the website allows researchers, journalists, and the public to access raw data, read the methodology of how those data were collected and processed, and improve them through their own contributions. WID.world datasets combine fiscal, survey and national account data in a novel, systematic way that produces reliable income time series and minimizes well known problems related to self-reporting and “under-reporting at the top.” Funds from this grant support the continued expansion and improvement of WID.world. Plans include expanding the number of countries covered to include China, India, Brazil, and several African states; improving data on the full income distribution; using collected income data to study issues such as tax fraud; improving the sites statistical tools; and adding new data variables like gender and environmental inequality. In addition, the research team will hold several workshops to facilitate use of the site and improve coordination with other researchers and large organizations such as the World Bank and IMF.