Edward G. Fox (Michigan; Google Scholar) & Zachary Liscow (Yale; Google Scholar), No More Tax-Free Lunch for Billionaires: Closing the Borrowing Loophole, 182 Tax Notes Fed. 647 (Jan. 22, 2024):

In this article, Fox and Liscow propose a tax on billionaires that would apply to borrowing against assets and explain how it could be designed and how it relates to other wealth tax proposals, as well as potential critiques.

Conclusion
We face high inequality and strong revenue needs in the United States.

Some object to taxing the wealthy unless they use their gains. But many of the wealthiest do use their gains through the borrowing loophole — they get rich, borrow against those gains, consume the borrowing, and do not pay any tax. This is unfair. Closing the borrowing loophole on the superrich would raise over $100 billion in an administrable, highly progressive, and reasonably efficient way.