NEW YORK, NEW YORK - JUNE 24: (L-R) Mira Nair, New York mayoral candidate, State Rep. Zohran Mamdani (D-NY) Rama Duwaji and Mahmood Mamdani celebrate on stage during an election night gathering at The Greats of Craft LIC on June 24, 2025 in the Long Island City neighborhood of the Queens borough in New York City. Mamdani was announced as the winner of the Democratic nomination for mayor in a crowded field in the City’s mayoral primary to choose a successor to Mayor Eric Adams, who is running for re-election on an independent ticket. (Photo by Michael M. Santiago/Getty Images) Getty Images Ever since Zohran Mamdani made a big splash by winning the Democratic nomination for Mayor of New York City in June of 2025, he has been thrust into the spotlight. Many, including Forbes, have opined on his tax policies that question whether he can raise over $10 billion in incremental revenues to pay for his ambitious plans by primarily raising taxes on the wealthy. The Rolling Stones recently published a story with a headline stating “Tax The Rich. They’ll Stay” as a nod to the “scant” evidence that raising taxes will affect whether wealthy taxpayers will leave the city when facing higher taxes. However, a key problem arises. The evidence from their article is mostly descriptive and based on associations. Meanwhile, evidence from academic studies that uses larger datasets using various setting and provides causal evidence suggests that the wealthy may leave, and the evidence is not “scant”. This article discusses some of the academic studies that examine this topic, and why wealthy taxpayer’s departures may be even more of a problem when considering a city tax. Academic Studies Showing Mamdani’s Tax May Lead To Wealthy Taxpayer Migration Whether wealthy taxpayers leave a jurisdiction when facing higher tax liabilities has been studied within the economics, finance, and accounting academic literatures. The findings have been rooted in the Scholes-Wolfson Framework, which suggests that taxpayers in a global planning framework should consider all taxes, all parties, and all costs. Thus, when a taxpayer faces an increase in explicit taxes, not unlike the increase Mamdani proposes for the wealthiest New York City residents, they are likely to weigh these costs against relocating. Of particular note, Cassidy, Dinecco, and Troiano’s published work in the American Economic Journal: Economic Policy in 2024 evaluates U.S. states that implemented an individual income tax from 1900 to 2010. They find that while the tax revenues per capita increase following taxes being imposed by states, it comes at a cost. In particular, the tax revenues for each taxpayer goes up but this result is, in part, because wealthy taxpayers leave. They suggest that these taxpayers have high mobility due to their resources, and the effects of the higher tax rates do not have their intended effect since the wealthiest taxpayers migrate out. These results align with Young, Varner, Lurie, and Prisinzano’s 2016 work published in American Sociological Review. Their study also uses a U.S. setting and shows significant migration among millionaires following states creating a so-called millionaire tax. The inferences from the literature are not just limited to the U.S. A study by Jakobsen, Kleven, Kolsrud, Landais, and Munoz in 2024 in the National Bureau of Economic Research series uses administrative data from Scandinavian countries. They find that a one percentage point increase in the top wealth tax rate results in measurable migration responses by wealthy taxpayers. These findings are also consistent with Agarwal and Foremny’s 2019 study in the Review of Economics and Statistics, which shows significant migration of the wealthiest taxpayers using the country of Spain as the research setting. Another study by Kleven, Landais, and Saez published in the American Economic Review in 2013 turns their attention to the football pitch. They examine whether professional soccer players in Europe consider taxes when relocating to a new soccer club. Their evidence suggests that once these athletes have an opportunity to choose a new team in a different jurisdiction, they gravitate toward those jurisdictions with lower income tax rates. As these athletes are typically very wealthy, the evidence is consistent with a mobility pattern that may persist if Mamdani’s tax plans go into effect. MORE FOR YOU Mamdani’s Tax Plan May Be Impounded By City-Level Taxes The studies above focus on taxes imposed on wealthy taxpayers at a country or state level. Potentially exacerbating the problem that Mamdani aims his tax plan at those living in New York City. As I previously discussed in a Forbes article, city taxes face an additional hurdle in that the migration does not have to be over a significant physical distance. New York City is a relatively small jurisdiction in area relative to states and countries. Wealthy taxpayers have the option to leave the city while still maintaining their work in the city itself. In fact, a very wealthy New York City resident potentially already owns real estate outside of the city. This potentially creates a situation where the taxpayer would be able to change their tax residence and avoid any incremental New York City taxes with minimal tax planning. Even more puzzling is the lack of consideration for how the economy has changed in the post-COVID-19 era. In the early 2020s, while facing the pandemic, Americans turned to remote work for their jobs. Even though many companies have returned to the office, the conditions are still in place that allow many taxpayers to work from home. If Mamdani’s tax plan is put into effect, these wealthy taxpayers may turn back to a remote or hybrid work environment to avoid bearing the burden of taxation in New York City. Lastly, it is problematic that wealthy taxpayers that might be considering a move to New York City may be less likely to do so in the future. For instance, Mamdani’s tax rate increase assumes the status quo in terms of taxpayers coming to New York City. Specifically, the plan assumes that there will continue to be migration of these wealthy taxpayers into the city. However, the plan does not account for the propensity for these taxpayers to locate outside the city or choose a different city all together. There is little doubt that some taxpayers will continue to stay in New York City even after Mamdani imposes his city tax on high earning taxpayers. In that regard, the proponents of imposing the tax have credible arguments that the tax rate increase will not result in all millionaires suddenly departing New York City. However, what is missing from these commentaries and Mamdani’s platform is evidence and analysis suggesting that wealthy New York City residents and corporations will remain in place to the point that it can sustainably generate $10 billion in additional tax revenues annually to fund his proposed social projects. A significant amount of academic evidence both in this article and beyond seems to be at odds with the expectation that wealthy taxpayers will stay put when facing higher tax burdens, and the problem might be exacerbated by the fact that these taxpayers may only need to move a few miles. Editorial StandardsReprints & Permissions