Commodity index
A commodity index tracks the price of a food commodity over time at a national or regional level. For a restaurant its value is diagnostic: when your beef price rises, the index tells you whether beef rose or whether your supplier did.
The two conversations it enables
- The market moved. Your supplier's increase is real and industry-wide. The response is repricing the affected dishes, not switching vendors — everyone else's price moved too.
- Only your price moved. The index is flat and your invoice isn't. That is a specific, evidenced conversation to have with your rep, and it is a much stronger position than "this feels expensive."
Public sources for US operators: the Bureau of Labor Statistics publishes average price series for common foods, and the Producer Price Index covers wholesale. Marji publishes a restaurant-framed version at the food cost index.
Worked example · Telling a market move from a vendor move
- Your butter price, January
- $3.90/lb
- Your butter price, June
- $4.72/lb
- Your increase
- +21%
- National index over the same period
- +19%
- Verdict
- market move — reprice, don't switch
Had the index been flat, that same 21% would be a vendor conversation with evidence behind it. Same invoice, opposite conclusion — which is exactly what the benchmark buys you.
Related terms
Price creep
Small, frequent supplier price increases that individually look ignorable and collectively remove several points of margin a year.
CPI: food away from home
The government measure of restaurant menu price inflation — what everyone else's prices are doing.
Market price (MP)
A menu listing with no printed price, used for items whose cost moves faster than the menu can be reprinted.
Seasonality index
A month-by-month multiplier describing how an ingredient's price or a restaurant's volume moves through the year.