| # | Finding | Key Data |
|---|---|---|
| 1 | Constitutional Gap | 4%: $952M of $2.24B β 57.5% unfunded |
| 2 | OOS Base Vanishes | $40.6B untaxable; $435M/yr lost |
| 3 | Concentration | Top 1%=15.1%; 49.7% OOS |
| 4 | Regressive Shift | Low: 8-10%; High: 3-4% |
| 5 | Geographic | Madison: 80% OOS, 9.43Γ |
| 6 | Property Types | 18.8% condos OOS; Powell TH 91.6% |
| 7 | No Scenario | 4%: $1.29B gap; 9.4%: highest in USA |
| Stakeholder | Property Tax | Sales Tax (6%) | Impact |
|---|---|---|---|
| 31,363 OOS Owners | $405.9M/yr | $0 | ESCAPE |
| 357,609 IS Owners | $1.83B | $1.43B + gap | BURDENED |
| Low-Income (<$30K) | Lower | 8-10% eff | REGRESSIVE |
| Per Household | β | +$1,889/yr | OOS=$0 |
| County | Parcels | OOS# | OOS% | Total Val | OOS Val | OOS%Val | OOS Avg | IS Avg | Prem | Risk |
|---|
| County | Top1% | Share | %OOS | Largest |
|---|---|---|---|---|
| STATE | 3,890 | 15.1% | 49.7% | $127.7M |
| Madison | 52 | 16.0% | 96.2% | $93.7M |
| Powell | 24 | 11.2% | 87.5% | $7.5M |
| Gallatin | 345 | 10.6% | 47.2% | $127.7M |
| Flathead | 455 | 9.2% | 49.9% | $62.4M |
| Tier | OOS# | IS# | OOS% | OOS Avg |
|---|---|---|---|---|
| <$250K | 5,420 | 91,580 | 5.6% | $148K |
| $250K-$500K | 9,840 | 115,160 | 7.9% | $375K |
| $500K-$1M | 7,900 | 92,100 | 7.9% | $720K |
| $1M-$3M | 5,200 | 29,800 | 14.9% | $1.85M |
| $3M-$10M | 2,150 | 3,750 | 36.4% | $5.2M |
| $10M+ | 853 | 697 | 55.0% | $18.5M |
| State | Props | Value | Avg |
|---|---|---|---|
| California | 6,424 | $7.95B | $1.24M |
| Texas | 2,161 | $3.53B | $1.63M |
| Florida | 1,422 | $3.22B | $2.27M |
| Washington | 3,488 | $3.11B | $892K |
| New York | 397 | $1.54B | $3.88M |
| Massachusetts | 229 | $1.04B | $4.52M |
MT Constitution caps sales tax at 4%. At 4%: $952M. Need: $2.24B. Gap: $1.288B (57.5%). Full replacement: 9.4% β highest in America. Amending requires 2/3 legislature + voter majority. Voters rejected 70-75% (1971, 1993).
31,363 OOS owners: $40.6B (18.1%). Avg $1.29M vs $510K IS (2.52Γ). ~$405.9M/yr property tax β $0 under sales tax. Per property: $13,864β$4,974 (β$8,890/yr).
Top 10% = 37.7%. Top 1% = 15.1%. 49.7% of top 1% is OOS. Largest property: $127.7M (Gallatin, OOS). 9/10 largest counties: OOS holds #1 property.
80% of $16.4B is OOS. Avg OOS: $8.5M vs IS $902K (9.43Γ). 96.2% of top 1% is OOS. 3,634 IS residents can't fund county alone.
Current MT ratio: 1.3Γ (among fairest). Sales tax states: 5-17Γ. Under swap: low-income 8-10% effective vs high-income 3-4%. Renters (36% HHs): 100% sales tax burden, 0% property tax benefit.
18.8% condos OOS (25.2% by value). $38.2B improved OOS (94.1% of total). Powell: 91.6% townhouses OOS. OOS pays more for LAND across all types. Vacation properties: full prop tax, zero sales tax.
500K PERT sims, 6 gates, R 4.3.3. 1 in 735,318. Zero sims >0.1%. Python+R converge. 8 statistical tests confirm (all p<2.2e-16, Cohen's d=3.44).
0/50 states ever replaced property tax with sales tax. MT: 0 for 8 over 58 years (1967-2025). Mathematical impossibility.
| Model | Method | Result |
|---|---|---|
| Bayesian | Beta(1,9) | P(ΞΈ>10%)=38.74% |
| Monte Carlo PERT | 500K sims, 6 gates | 0.000136% |
| Sensitivity | Tornado | Most: bipartisan 2/3 |
| Voter | Beta(136001,364001) | P(Yes>50%)<10β»Β²β° |
| Revenue Bootstrap | 100K iterations | P(gap>$0)=100% |
Learn how to use the What-If Simulator to test any policy proposal. Click below to start the guided walkthrough, or read the quick reference.
Sales Tax Rate: Drag 0-12%. Red zone (>4%) = unconstitutional.
Property Tax Retained: 0%=full replacement, 50%=hybrid, 100%=no change. The key insight: even partial replacement loses OOS revenue proportionally.
Standard: Toggle groceries (-18%), medicine (-4%), clothing (-8%), services (-12%).
Custom: Click "+ Add Custom Exemption" to model anything: farm equipment, utilities, vehicles, school supplies. Name it, set the % of base it removes.
Economy: Pandemic=-30%, Recession=-15%, Boom=+15%. Sales tax is pro-cyclical β revenue crashes in bad times. Property tax is stable.
Border Leakage: Shoppers flee to ID/WY. -10% to -30% realistic for border counties.
K-12 Floor: Guarantees $1.34B for schools β exposes how much your scenario falls short.
Charts: 6 live charts update instantly. Donut=revenue sources. Waterfall=gap math. Burden=regressivity. Counties=vulnerability.
| Scenario | Settings | What You'll See |
|---|---|---|
| Default (4% cap) | Rate 4%, 0% retained | $1.29B gap, $2,996/HH, 57.5% unfunded |
| Kitchen Sink | 6% + all exemptions | Gap GROWS β exemptions reduce base by 42% |
| Hybrid 50/50 | 4% rate, 50% retained | Gap shrinks but still $650M+ short |
| Pandemic + Sales Tax | 4%, economy=Pandemic | Revenue drops 30% β catastrophic for schools |
| Maximum Effort | 12% rate, 0% retained, no exemptions | Finally closes gap β but rate is 3Γ cap, unconstitutional, and highest in world |
| The Real Question | Any rate, 100% retained | No change needed. Current system works. |