The tax bill approved by the House Ways and Means Committee on November 9 is fiscally irresponsible. The bill would cost nearly $1.5 trillion over the decade, according to Joint Committee on Taxation (JCT) estimates. But provisions in the bill that would phase in slowly or expire after several years obscure the bill’s true cost and would almost certainly drive the ultimate cost even higher.

Further, the costs would continue beyond the ten-year window shown in the official cost estimates, adding substantially to the nation’s debt burden. A new analysis by Penn Wharton economists that also takes into account the bill’s effects on the economy and the interest burden from higher debt levels estimates that it would add roughly $3 trillion to the debt between 2028 and 2037, the next decade beyond the current ten-year budget window.

Current Fiscal Outlook Doesn’t Support House Bill’s Irresponsible Tax Cuts

Today’s tax debates are taking place in a substantially different fiscal environment than when past tax cuts were debated. Compared to 1981, when the Reagan tax cuts were passed, and 2001, when the Bush tax cuts were enacted, revenues today are lower and the debt held by the public is considerably higher, measured as a percent of the economy. (See Figure 1.)

In 2001, the federal government was running a surplus, the federal debt was shrinking, and large surpluses were forecast for the coming decade. Today’s fiscal outlook is the opposite.And the budget outlook is vastly different, particularly compared to when the 2001 Bush tax cuts were being considered.[1] In 2001, the federal government was running a surplus, the federal debt was shrinking, and large surpluses were forecast for the coming decade. Today’s fiscal outlook is the opposite: deficits are growing and the debt is projected to rise from today’s 77 percent of gross domestic product (GDP) to 91 percent in 2027, according to the Congressional Budget Office (CBO), due to rising health care and other costs associated with the retirement of baby boomers, as well as the significant ongoing costs of the Bush tax cuts. (See Figure 2.)

Despite these looming fiscal pressures, congressional Republican leaders have abandoned their earlier pledges to pursue revenue-neutral tax reform. Instead, they’re aggressively advancing a costly tax cut. Together, the bill’s revenue loss and associated debt service costs would add $1.7 trillion to deficits and debt between 2018 and 2027, and would bring the debt to 97 percent of GDP by 2027.

Bill’s True Cost Is Higher Than Advertised

The bill’s cost is almost certainly understated in these estimates, however, because two of its major provisions would sunset (i.e., end) in 2023, in order to artificially hold down the bill’s cost so that it complies with the rules established in the fiscal year 2018 congressional budget resolution, which restrict the size of the tax cut in this bill to $1.5 trillion over ten years.[2] These two provisions are:

A new $300 non-refundable tax credit for non-child dependents. This provision helps protect many middle-income people from facing a tax increase due to other provisions in the bill, such as the elimination of the personal exemption. But under the bill, this provision is slated to expire in 2023. That’s a major reason that the number of people facing tax increases would rise over time, according to the JCT estimates. In response, Chairman Brady and other Republican lawmakers have said explicitly that policymakers would come back and extend the provision before it expires[3] — essentially acknowledging that the scheduled expiration of this tax credit in 2023 is a budget gimmick.

A generous deduction for business investments. The bill would let businesses deduct the cost of certain investments — such as in factories and equipment— in the year in which they’re made, instead of following the current practice of deducting their cost over time as the factories and equipment wear out (i.e., as they “depreciate” or decline in value). This provision, known as “full expensing,” would start immediately but then expire in 2023. With full expensing removed, businesses would pay more in tax than they would otherwise, as they couldn’t deduct depreciation costs on investments they’ve already fully expensed. That’s one of the main reasons that the JCT estimates show the bill’s business provisions causing a tax increase on businesses in 2023.[4] Policymakers would very likely extend this provision, just as they have extended similar so-called “temporary” provisions that give businesses more generous deductions for investments in buildings and equipment.[5]

While there are no JCT estimates of the cost of extending these two provisions, the Committee for a Responsible Federal Budget estimates that continuing them after their expiration in 2023 would add roughly $400 billion to the cost of the bill over the decade.[6] These additional costs and the associated debt service would boost the debt-to-GDP ratio to 99 percent by 2027.

House Bill’s Tax Cuts Would Have Substantial Long-Run Effects

The bill’s cost will continue beyond 2027, adding to the nation’s debt for years to come, a new analysis by economists at the University of Pennsylvania’s Penn Wharton Budget Model finds.[7] The Bush tax cuts — which were first enacted in 2001 and then mostly made permanent following the “fiscal cliff” debate at the end of 2012 — provide an important lesson, as they represent a permanent loss of revenue that continues to add to the debt. (See box.) The cost of the Bush tax cuts, as amended, from 2001-2018 accounts for about one-third of the entire $15 trillion debt held by the public in 2018, we estimated in a 2013 study.[8]

Supporters of the House tax bill often claim that its positive effects on the economy will counter its large revenue losses, effectively removing any impact on the deficit. But the Penn Wharton estimates conclude otherwise. They estimate that the bill would increase the size of the economy above current projections by between 0.4 percent and 0.9 percent by 2027 — meaning it would only add between 0.04 percent and 0.1 percent to economic growth each year, on average. Further, the Penn Wharton study concludes that “this initial boost fades over time as more debt accumulates.” Even after taking the bill’s growth effects into account, Penn Wharton finds it would add roughly $3 trillion to the debt in the next ten-year period (2028-2037) beyond the official budget window.

Other estimates, such as those by the Tax Foundation, show higher economic growth effects from the House bill than Penn Wharton.[9] But the Tax Foundation’s estimating model relies on assumptions that are well outside the economic mainstream. [10] For instance, the Tax Foundation makes very aggressive assumptions about how certain tax changes affect decisions to work, save, and invest and thereby generates outsized estimates of the responses to various tax policy changes. It also ignores any impact of unpaid-for tax cuts on budget deficits and debt; in contrast, CBO and JCT assume, based on the empirical evidence, that higher deficits lead to a reduction in national savings and investment, ultimately lowering future economic output compared to what it otherwise would be. Yet even with these larger growth effects, the Tax Foundation still shows that the bill would fall far short of paying for itself, adding $1 trillion to deficits over the first ten years. (President Trump’s Council of Economic Advisers also claims that a tax cut like the House bill would have large growth effects, particularly on workers’ wages, but mainstream economists have sharply criticized those estimates as being highly implausible.[11])