In 2021, the U.S. "tax gap" (difference between taxes owed and collected) totals around $600 billion, annually. The vast majority (roughly 65%) of dodged taxes are accounted for by the top 10% of the income distribution.
Over the next 10 years, the present tax gap represents roughly $7 trillion dollars of uncollected tax revenue. The majority of uncollected revenue stems from those with top incomes. The primary cause of the tax gap is identified as an under-staffed IRS with outdated technology, leaving them unable to collect 15% of taxes owed. The author estimates that an extra $80 billion in IRS funding could generate an extra $320 billion over the next decade. Allowing the IRS to use information from financial institutions - at no cost to taxpayers - is estimated to raise an extra $460 billion over the next decade.