In another thread, someone else suggested $10M and I suggested $100M. (This is wealth, i.e., total assets / net worth, not annual income.)

The 99th percentile ("top 1%") of wealth by household seems to have been be $8.4M in 2007, according to https://economix.blogs.nytimes.com/2012/01/17/measuring-the-..., the most recent calculation I could find from a quick Google before heading to work - I'd love to see these calculations done with the raw data at https://www.federalreserve.gov/econres/scfindex.htm . From the summary on that page, they surveyed some 116 million households in 2007.

Suppose you tax all holdings at the top 1% of wealth by 1%/year, which is significant but not enough to wipe you out - after 50 years that leaves you with 60% of your original savings, assuming you weren't investing it.

That yields as a minimum $97T in tax revenue per year ($8.4M * 1.16M * 1%), and almost certainly significantly more because there-s a short tail of people with much more than $8.4M net worth. But if you split even this much among the 5% of households with "very low food security", that's $16,800/year. That's a lot of food.

(An actual scheme would have some sort of progressive tax, also, not a discontinuity at a certain dollar value)