The Main Street Price Index™ (MSPI)
An Inflation Index for Main Street America
A basket of household essentials that cost $100 in 1983 costs $424 today. The official Consumer Price Index (CPI) puts that same basket at $331. Both figures come from the same government data — the U.S. Bureau of Labor Statistics. The difference is the basket.
Data through May 2026 · Updated monthly with BLS CPI release
Key Numbers (2026, Base 1983 = 100)
What Is MSPI?
The Consumer Price Index (CPI) averages across hundreds of spending categories — from pet food to airline tickets to electronics. MSPI tracks only the 6 categories households cannot opt out of:
- Shelter — rent of primary residence, owners' equivalent rent, tenants' insurance (53.6% of MSPI basket)
- Food at Home — groceries, not restaurant meals (12.6% of MSPI basket)
- Medical Care — insurance, services, and prescriptions (13.0% of MSPI basket)
- Work-Related Transportation — motor fuel, vehicle insurance, vehicle maintenance (10.7% of MSPI basket)
- Utilities — household energy, water, sewer, and trash (6.8% of MSPI basket)
- Connectivity — wireless telephone and internet service (3.5% of MSPI basket)
Together these account for about two-thirds of the CPI by weight. Dining out, airfare, hotels, new vehicles, electronics, clothing, and recreation are excluded — not because they are unimportant, but because they can be deferred or substituted in ways that shelter and medical care cannot.
Same BLS data. Same Laspeyres index math. Different basket.
Historical Index Levels (MSPI vs CPI, Base 1983 = 100)
| Year | MSPI | CPI | Gap (%) |
|---|---|---|---|
| 1983 | 100 | 100 | — |
| 1990 | 140 | 131 | +6.9% |
| 1995 | 165 | 153 | +7.8% |
| 2000 | 190 | 173 | +9.8% |
| 2005 | 226 | 196 | +15.3% |
| 2010 | 258 | 219 | +17.8% |
| 2015 | 288 | 238 | +21.0% |
| 2020 | 324 | 260 | +24.6% |
| 2024 | 401 | 315 | +27.3% |
| 2026 | 424 | 331 | +28.1% |
Component Price Growth, 1983–2026
| Essential | Price Multiplier | MSPI Weight | Note |
|---|---|---|---|
| Shelter (OER) | ~4.3× | 41% | Largest single driver |
| Shelter (Rent) | ~4.4× | 12% | Sets the housing floor |
| Medical Care | ~5.9× | 13% | Resistant to efficiency gains |
| Vehicle Insurance | ~8.9× | 4% | Steepest single component |
| Food at Home | ~3.2× | 13% | Steady and broad-based |
| Motor Fuel | ~3.3× | 5% | Volatile; ends above 1983 |
| Household Energy | ~2.9× | 5% | Volatile year to year |
| Connectivity | declined | 3% | Only essential that grew cheaper |
2050 Projection (2% Annual Growth Scenario)
If both the MSPI and CPI grow at the Federal Reserve's 2% annual inflation target from 2026, by 2050 the CPI basket would cost approximately $533 and the MSPI basket approximately $682 — a dollar gap of ~$149, up from ~$93 today.
"The Federal Reserve aims for inflation of about 2 percent a year. The target is often read as a return to stable prices. It is not. It is a policy of steady increase. Prices are meant to rise about 2 percent every year, without end."
— Munir Moon
⚠ Projection assumes 2.00%/yr for both indices from 2026. Illustrative only — not a forecast.
How MSPI Compares to Other Benchmarks (2026)
| Measure | 2026 Level (1983 = 100) |
|---|---|
| Official CPI | 331 |
| Core CPI (ex-food & energy) | 336 |
| Cleveland Fed Trimmed Mean | 332 |
| MSPI (Essentials Only) | 424 |
The MSPI floor sits 26–28% above all standard benchmarks.
Methodology
MSPI uses the same fixed-weight Laspeyres method the BLS uses for the CPI and its sub-indexes (such as Core CPI). Construction involves four steps: (1) select the essential categories; (2) take their official weights from the BLS relative-importance tables; (3) remove the rest; and (4) rescale the remaining weights so they sum to one.
MSPI differs from the CPI for exactly one reason: discretionary items are excluded. Every input is from official government sources. The CPI and each component come from the BLS as annual averages of monthly indexes. The weights are the BLS relative-importance figures for December 2024 — the most recent complete table at the time of construction. The index begins in 1983 because that is the year the BLS adopted owners' equivalent rent, allowing consistent shelter measurement throughout.
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About the Index
MSPI is an independent, non-partisan price index built entirely from public BLS data. It is maintained by Munir Moon — a UCLA-trained economist (B.S. Engineering, M.S. Economics, M.B.A. Finance), former financial industry executive, and author of three books on the American middle class. No institutional funding. No political affiliation. Data updates monthly with the BLS CPI release.
MSPI is a complement to the Consumer Price Index — not a replacement. It is independent and not affiliated with, endorsed by, or produced by any government agency.
Data source: BLS Consumer Price Index, U.S. city average, not seasonally adjusted. Weights from BLS Relative Importance of Components, December 2024.
© 2026 Main Street Price Index. All rights reserved. MSPI™ and Main Street Price Index™ are trademarks pending.