Closing the $688 billion tax gap won't help solve the US debt problem

The IRS is promising its focus on increased tax compliance will help with the nation’s debt problem.

"Achieving our goals will result not only in a fairer tax system," IRS commissioner Danny Werfel testified before Congress in October, "but also in benefits for taxpayers and the nation because detecting and stopping noncompliance in these areas would result in significant additional revenues and reduce the deficit."

Not so fast, says one expert.

Even if the Internal Revenue Service achieves a 100% collectible rate, up from the current 86.3% net compliance rate, and closes the estimated $688 billion tax gap, that won’t be enough to meaningfully shrink the chasm between how much the US spends versus how much revenue it takes in.

"You're running a $1.7 trillion dollar deficit," Scott Hodge, president emeritus and senior policy adviser at the Tax Foundation, told Yahoo Finance. "Even perfect tax compliance — an impossible goal — would fall short of eliminating the deficit."

The IRS estimated that the national tax gap was $688 billion in 2021, up 14.4% from $601 billion in 2020 and nearly double from $345 billion in 2001. It attributed the tax gap increase to a growing US economy.

For instance, 2021’s estimated tax gap accounted for 2.6% of overall gross domestic product, or GDP, which was $23 trillion in the same period. This ratio has largely stayed consistent since 2014 — oscillating between 2.3% and 2.6% — demonstrating that both elements grow correspondingly.

"While $688 billion sounds like a big number and is touted as a big increase from prior years, it is hardly different as a share of the economy than the tax gap figures from prior years," Hodge wrote.

Tax collections were also relatively stable when compared to GDP. Between 2015 and 2021, the share of IRS revenue collection has ranged between 16.4% to 18.3% of GDP, while gross revenue continued to climb at an average rate of 3.2%. Revenue collected reached $4.1 trillion in 2021, but the highest GDP share ratio was 18.3% in 2016 when the IRS collected $3.3 trillion in revenue.

Yet the agency's revenue has not kept pace with federal spending. Federal spending was $7.65 trillion in 2021, $6.5 trillion in 2022, and $6.13 trillion in 2023.

The federal government's share of spending compared to GDP has clocked in between 20% to 30% between 2015 and 2021, government data shows. This is much higher than the tax collection-to-GDP ratio of 16.4% to 18.3% in that same period.

So even if the IRS collects 100% of estimated revenue and closes the tax gap by hundreds of billions of dollars, the government still can't meet its growing deficit.