Our Methodology

📦 What We Track

Our inflation tracker monitors over 100 everyday household items across multiple categories:

• Groceries: Eggs, milk, bread, meat, produce, pantry staples
• Energy: Gasoline prices (national and regional averages)
• Household Essentials: Cleaning supplies, paper products, personal care
• Common Purchases: Electronics, clothing, home goods

Based on a subset of the Consumer Price Index (CPI) basket, weighted toward items people purchase frequently.

🏪 Retailer Coverage

We collect prices from major national retailers to ensure broad market representation:

• Amazon
• Target
• Walmart
• CVS
• Other regional and specialty retailers

⚙️ Data Collection Process

Our automated system tracks prices daily:

1. Automated Price Scraping: We use reliable web scraping technology to collect current prices from retailer websites
2. Data Validation: Prices are checked for anomalies and outliers to ensure accuracy
3. Historical Storage: All price points are stored with timestamps for trend analysis
4. Daily Updates: The tracker refreshes every 24 hours to capture the latest pricing

📊 How We Calculate Inflation

Index Calculation:

• We establish a baseline index (set at 100) from our starting measurement period
• Each product category is weighted based on typical household spending patterns
• Price changes are aggregated across all tracked items to produce a composite index

Reporting Metrics:

• Current Index: The current composite price level relative to our baseline
• Year-over-Year (YoY): Percentage change compared to the same period last year
• Month-over-Month (MoM): Percentage change from the previous month

🎯 Why This Matters

Traditional inflation metrics like CPI are valuable but:

• Released monthly with a lag (typically 2-4 weeks after month end)
• Include services and housing costs that don't reflect daily purchasing
• May not capture what individual households actually experience

PriceSignal focuses on real-time, tangible items that people buy regularly, providing a more immediate and relatable view of inflation's impact on household budgets.

🔬 Transparency & Limitations

What we do well:

• Daily tracking of widely-purchased items
• Real-time visibility into price changes
• Cross-retailer price comparison

Known limitations:

• Our basket is smaller than official CPI measurements
• Regional variations may not be fully captured
• Sale prices and promotions can create short-term volatility
• We track list prices, not actual transaction prices with coupons/discounts

We believe in transparency about what our data shows and what it doesn't. PriceSignal is a complementary tool to official inflation measures, not a replacement.