9a181ae43b
Added SUMMARY.md executive summaries to all 7 datasets with: - 🎯 BEST ESTIMATE section at top - 12-word one-liners for quick reference - Confidence levels and caveats - Extensive authoritative linking - Alternative Estimates sections where applicable - Changelogs for revision tracking Updated Data/README.md with: - Quick reference table of all datasets - Full schema documentation - Confidence level guidelines - Anti-patterns to avoid Datasets standardized: - Knowledge-Worker-Global-Salaries (gold standard) - US-GDP - US-Inflation - US-Presidential-Approval - Bay-Area-COVID-Wastewater - US-Common-Metrics - Pulitzer-Prize-Winners 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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U.S. Inflation (CPI): Executive Summary
🎯 BEST ESTIMATE
| Metric | Value | Confidence | Last Updated |
|---|---|---|---|
| CPI-U Index (August 2025) | 323.4 | 99% | October 2025 |
| Year-over-Year Inflation | ~2.5% | 99% | October 2025 |
| Fed Target | 2.0% | Reference | - |
One-liner: U.S. inflation is ~2.5% (YoY), with CPI index at 323.4 (1982-84=100 baseline).
Caveat: CPI measures urban consumers only (~93% of population); regional variation may differ significantly.
The Big Picture
The Consumer Price Index (CPI) is the primary measure of inflation in the United States—tracking changes in the price level of a basket of consumer goods and services. The Bureau of Labor Statistics (BLS) produces this data monthly.
What the current numbers mean:
- A CPI of 323.4 means that goods costing $100 in 1982-84 now cost $323.40
- At 2.5% annual inflation, prices double approximately every 28 years
- Current inflation is near the Federal Reserve's 2% target
Why This Number Matters
Inflation affects virtually every economic decision:
- Wages: Cost-of-living adjustments (COLAs) are tied to CPI
- Savings: Determines whether your money gains or loses purchasing power
- Interest Rates: The Federal Reserve adjusts rates based on inflation
- Contracts: Many business and government contracts escalate with CPI
- Policy: Trillions in Social Security, Medicare, and tax brackets adjust with CPI
A 1% change in CPI affects billions of dollars in annual adjustments.
Current Data Highlights
Recent Readings
| Period | CPI Index | YoY Inflation | Source |
|---|---|---|---|
| August 2025 | 323.4 | ~2.5% | BLS |
| June 2022 | 296.3 | 9.1% (peak) | BLS |
| 1982-84 Avg | 100.0 | Baseline | BLS |
| January 1947 | 21.5 | First obs. | BLS |
Long-Term Trend
| Period | Average Annual Inflation |
|---|---|
| 1947-2025 (Full) | ~3.5% |
| 1990-2019 (Pre-COVID) | ~2.4% |
| 2021-2023 (COVID Surge) | ~6.0% |
| 2024-2025 (Current) | ~2.5% |
How the Number Is Calculated
The BLS uses a Laspeyres price index:
CPI = (Cost of basket today / Cost of basket in base period) × 100
The Market Basket
| Category | Weight | Examples |
|---|---|---|
| Housing | ~34% | Rent, utilities, furnishings |
| Food | ~14% | Groceries, restaurants |
| Transportation | ~16% | Vehicles, gas, insurance |
| Medical Care | ~9% | Healthcare, drugs, insurance |
| Recreation | ~5% | Entertainment, sports, hobbies |
| Education/Communication | ~7% | Tuition, phones, internet |
| Other | ~15% | Apparel, personal care |
Data Collection:
- ~80,000 prices collected monthly
- 75 urban areas across the U.S.
- Weights updated every 2 years from Consumer Expenditure Survey
Key Inflation Rates to Know
| Measure | What It Is | FRED ID |
|---|---|---|
| Headline CPI | All items | CPIAUCSL |
| Core CPI | Excludes food & energy | CPILFESL |
| PCE | Fed's preferred measure | PCEPI |
| Core PCE | Fed's key target | PCEPILFE |
Why Core? Food and energy prices are volatile. Core inflation shows underlying trends.
Why PCE? The Federal Reserve targets PCE inflation rather than CPI because it accounts for substitution effects.
Historical Inflation Episodes
| Period | Peak Inflation | Cause |
|---|---|---|
| 1970s Stagflation | 14.8% (1980) | Oil shocks, monetary policy |
| Volcker Shock | Fed raised rates to 20%+ | Broke inflation cycle |
| Great Moderation | 2-3% (1990s-2000s) | Credible monetary policy |
| Great Recession | Brief deflation (2009) | Financial crisis |
| COVID Surge | 9.1% (June 2022) | Supply chain, stimulus |
| Current | ~2.5% (2025) | Fed tightening working |
Confidence Assessment
| Component | Confidence | Explanation |
|---|---|---|
| Current CPI Index | 99% | Official government statistic, gold standard |
| YoY Inflation Rate | 99% | Direct calculation from CPI data |
| Historical Data | 99%+ | Fully verified, minimal revisions |
This is the most reliable inflation data available—produced by the U.S. government with rigorous methodology and complete transparency.
Known Limitations
- Substitution bias: Fixed basket doesn't fully capture when consumers switch to cheaper alternatives
- Quality adjustment: Hard to account for product quality improvements over time
- New products: Slow to incorporate new goods (smartphones took years)
- Geographic variation: National average masks significant regional differences
- Population: Covers urban consumers only (~93% of U.S.)
How to Calculate Inflation
Year-over-Year Rate
Inflation Rate = ((CPI_now - CPI_1year_ago) / CPI_1year_ago) × 100
Convert Dollars Across Time
Real_value = Nominal_value × (CPI_target_year / CPI_original_year)
Example: $100 in 1984 equals ~$323 in 2025 purchasing power.
Data Sources
| Source | What It Provides | Link |
|---|---|---|
| Bureau of Labor Statistics | Official CPI (primary authority) | CPI Home |
| FRED | Easy API access to BLS data | CPIAUCSL |
Quick Access:
# Download latest CPI data from FRED
curl -L "https://fred.stlouisfed.org/graph/fredgraph.csv?id=CPIAUCSL" -o CPI-latest.csv
Supporting Documentation
| Document | Description |
|---|---|
| US-Inflation-CPI-1947-2025.md | Full dataset documentation |
| source.md | Detailed methodology |
| CPI-US-Monthly-1947-2025.csv | Monthly data (945 observations) |
Research Metadata
| Attribute | Value |
|---|---|
| Research Date | October 2025 |
| Researcher | Kai |
| Method | Direct BLS/FRED data collection |
| Confidence Level | 99% (official government statistic) |
| Known Gaps | Pre-1947 data uses different methodology |
Changelog
| Date | Change | Reason |
|---|---|---|
| December 2025 | Added SUMMARY.md with executive overview | Standardizing Substrate datasets to "Answer First" schema |
| October 2025 | Initial dataset creation | Comprehensive U.S. CPI data collection |
External Resources
- BLS CPI FAQ - Common questions
- BLS Handbook of Methods - Full methodology
- Fed Inflation Target - Why 2%?
- CPI Inflation Calculator - BLS tool