Dave Helling recently responded to my Show-Me Institute colleagues’ piece on what Missouri should learn from Kansas’s tax changes a decade ago. He questions whether Missouri’s current discussion is meaningfully different from what happened under former Kansas Gov. Sam Brownback.
I respect Dave and welcome the debate. Kansas belongs in this conversation. But if we are going to invoke it, we should be clear about what it demonstrates.
Kansas did not experience instability simply because it lowered tax rates. It ran into trouble because revenue fell precipitously and the state did not appropriately adjust its fiscal structure. Lawmakers enacted sharp tax reductions, created a large pass-through exemption, and left spending commitments largely intact. The result was a structural imbalance.
That is the lesson.
Dave suggests that state tax policy has only a marginal relationship to economic growth. It is true that no state controls the national business cycle. But it does not follow that tax structure is economically irrelevant.
Growth reflects millions of individual decisions—where to work, invest, expand, or relocate. Tax policy influences those decisions at the margin. And marginal decisions, aggregated across an economy, shape long-run performance.
If tax policy does not meaningfully affect behavior, it becomes difficult to explain why businesses restructured to qualify for Kansas’s pass-through exemption, why cities such as Kansas City offer tax abatements and other tax incentives to attract employers, or why area policymakers worry about the Border War. Incentives matter. They always have.
Both Kansas City and St. Louis are about to vote on retaining their 1% earnings taxes. Does anyone doubt the tax is one more incentive to live and work outside city limits?
None of this means that tax cuts guarantee prosperity. Lower rates increase the after-tax return to work and investment; they do not override broader economic conditions. But acknowledging limits is not the same as declaring irrelevance.
Kansas was not a clean test of “supply-side theory.” It did not eliminate its income tax. It reduced rates quickly, carved out a significant exemption, and failed to align revenue reductions with sustainable fiscal adjustments. When revenues declined more than expected, the state lacked sufficient buffers.
That was a structural failure, not proof that tax policy is immaterial.
Missouri’s debate, then, should center on structure and discipline. Any serious reform would require conservative revenue estimates, a modernized and stable tax base, adequate reserves, and spending aligned with realistic collections. Without those elements, skepticism is warranted. With them, instability is not inevitable.
There is also a tension in arguing that tax policy has little influence on economic outcomes while simultaneously warning that changing it risks serious harm. If tax structure truly operates only at the margins, its effects—positive or negative—cannot be dismissed when convenient and amplified when politically useful.
The more accurate position lies between extremes. Tax structure is neither a magic lever nor a null variable. It is one component of competitiveness, and like any component, it must be designed responsibly.
Kansas offers a caution about execution. But the Kansas story does not settle the broader question of how Missouri should structure its tax system going forward.
That question deserves a debate grounded in fiscal mechanics and economic incentives instead of caricatures.