The Arithmetic of a 30% Corporate Rate
Proposals to raise the corporate income tax rate from 21% to 28% or 30% are central to debates over budget reconciliation. However, dynamic scoring models suggest that rate increases alone yield diminishing returns due to profit shifting and investment disincentives.
Static vs. Dynamic Scoring
In a static model, every 1 percentage point increase in the corporate tax rate yields approximately $130 billion over a 10-year budget window. Therefore, moving from 21% to 30% theoretically generates nearly $1.2 trillion.
Dynamic scoring, utilizing models from the Joint Committee on Taxation (JCT) and the Penn Wharton Budget Model (PWBM), paints a different picture. Higher corporate rates depress after-tax returns on investment, leading to a smaller capital stock, lower productivity, and slightly lower wages over the long run.
The Base Broadening Alternative
Tax policy experts generally prefer base broadening—eliminating deductions and credits—to rate increases. A lower rate applied to a broader base reduces economic distortions.
For example, pairing a modest rate increase (e.g., to 25%) with stricter limitations on the deductibility of interest expense and full expensing for R&D can generate similar revenue to a 30% rate while mitigating the negative macroeconomic effects.
Worked Example: The Base-Broadening Tradeoff
Scenario A: Rate Increase Only
- Statutory Rate: 28%
- Deductions: Status Quo
- Dynamic 10-Yr Revenue: +$850 Billion
- GDP Impact (Yr 10): -0.4%
Scenario B: Base Broadening
- Statutory Rate: 25%
- Deductions: Eliminate strict interest deductibility, modify foreign derived intangible income (FDII).
- Dynamic 10-Yr Revenue: +$820 Billion
- GDP Impact (Yr 10): -0.1%
Conclusion: Scenario B raises nearly identical revenue with a fraction of the macroeconomic drag.
Common Mistakes in Analysis
Mistake: Ignoring Corporate Incidence
Corporations do not "pay" taxes; they remit them. The economic burden (incidence) falls on shareholders, workers (via lower wages), and consumers (via higher prices). The CBO assumes roughly 25% of the corporate tax burden falls on labor, though some academic estimates place it higher.
Frequently Asked Questions
Run the Yield Estimator
Adjust statutory rates and base-broadening measures to estimate dynamic revenue scoring impacts.
Launch Corp Tax ModelScenario A: Rate Increase Only
- Statutory Rate: 28%
- Deductions: Status Quo
- Dynamic 10-Yr Revenue: +$850 Billion
- GDP Impact (Yr 10): -0.4%
Scenario B: Base Broadening
- Statutory Rate: 25%
- Deductions: Eliminate strict interest deductibility, modify foreign derived intangible income (FDII).
- Dynamic 10-Yr Revenue: +$820 Billion
- GDP Impact (Yr 10): -0.1%
Conclusion: Scenario B raises nearly identical revenue with a fraction of the macroeconomic drag.
Common Mistakes in Analysis
Mistake: Ignoring Corporate Incidence
Corporations do not "pay" taxes; they remit them. The economic burden (incidence) falls on shareholders, workers (via lower wages), and consumers (via higher prices). The CBO assumes roughly 25% of the corporate tax burden falls on labor, though some academic estimates place it higher.