What is the Personal Wealth Study? The Personal Wealth Study uses information reported on Form 706, United States Estate (and Generation Skipping Transfer) Tax Return, to estimate the wealth of the living population. These estimates, based on the Estate Multiplier technique appear every three years. The estimates are limited to that segment of the population for whom personal wealth is at least equal to the estate tax filing threshold in effect for the estimation period. This page provides additional information about data produced in SOI's Personal Wealth Study. Please click on a link below to get started. • Selected Terms and Concepts • Data Sources and Limitations Please visit Personal Wealth Statistics for data tables and articles from the study.