The richest 1% of people in 2019 are not quite the same individuals as the richest 1% of 2009.

Judged as of 2019-12-29. The claim is hedged ('not quite the same'): it says the membership of the top 1% of wealth (or income) in 2019 differed meaningfully from 2009. True: wealth or income mobility data (panel studies, tax-record studies, or rich-list turnover such as Forbes 400 or Bloomberg) show substantial turnover, meaning a non-trivial share of 2009's top 1% were no longer in the top 1% by around 2019. Mostly true: turnover is documented but the data cover a nearby period or a proxy (e.g. top 400 rather than the top 1%), or are for one country only. Mixed: evidence is split, e.g. high turnover in income but near-complete persistence in wealth. Mostly false: the evidence shows membership is almost entirely persistent and turnover is negligible, with only a small fringe changing. False: the evidence shows the two groups are essentially identical.

Set before the research began.

1. E1 DavidSplinter.com DavidSplinter.com (personal research site of economist David Splinter)

   “After a decade, two-thirds of those who started in the top 1% are no longer there.”

2. E2 Our top 1% of income earners is an increasingly entrenched elite Phys.org (republished from The Conversation) · 4 November 2021

   “For example, 64% of people in the top 1% in 1991 were still in the top 1% a year later.”

3. E3 Tossed and Turned: Wealth Dynamics of U.S. Households 2007-2009 Board of Governors of the Federal Reserve System (FEDS working paper) · 7 November 2011

   “Of those who were present in the Forbes list in 2007, 61 (15.3 percent) were no longer present in 2009 (11 of them had died)”

4. E4 The characteristics and incomes of the top 1% | Institute for Fiscal Studies Institute for Fiscal Studies · 6 August 2019

   “on average around 10,000 (1.1%) were in the top 1% in any given year between 2000–01 and 2015–16, but three times as many (i.e. 31,000, or 3.4%) had been in the top 1% at some point over that period.”

E1 says that, after a decade, two-thirds of people who started in the top 1% are no longer there. That is substantial ten-year turnover, but the quote does not say it covers 2009–2019. In UK tax data, E4 finds that about three times as many people were in the top 1% at some point between 2000–01 and 2015–16 as in any single year. E2 reports that 64% of people in the top 1% in 1991 were still in the top 1% a year later. E3 shows 15.3% of the Forbes 400 list changed between 2007 and 2009. The evidence consistently shows meaningful turnover, but it covers nearby periods, income rather than wealth, or a rich-list proxy, not 2009 to 2019 itself. That fits the criteria for mostly true.