Patterns of Pass-through of Commodity Price Shocks to Retail Prices

Commodity prices have been rising at unprecedented rates over the last two years. The primary objective of this paper is to assess if and how firms pass through upstream cost increases to final good prices. First, we investigate what happens to the shelf prices (the regular prices) of goods that contain significant amounts of a commodity whose price has changed. The objective is to document patterns of price rigidity depending on the share of the commodity in the final good that is sold to consumers. For example, given an abnormal commodity price change in wheat, what happens to the shelf regular price of bread, wheat cereals, and other goods that contain wheat? Commodity pass-through patterns for ready to eat cereal (smallest share of commodity in final product) and fresh chicken (largest share of commodity in final good) are investigated. Second, we also assess what happens to the net prices consumers pay (that is the regular price net of discounts offered). One possible way to pass through a cost increase is to reduce the frequency of promotional discounts, or offer smaller discounts to consumers. Upstream commodity input prices used in our investigation are wheat and corn futures prices, to account for upstream inputs, and flour and chicken feed producer price sub indices for downstream cost shocks. We combine several datasets for this empirical analysis: commodity prices, commodity price indices, and scanner data on prices for a variety of goods, over a four year time period and across several stores in California, belonging to a large retail chain. We construct quantity weighted price indices within two product categories sold in the supermarket, where prices are weighted by pre-determined quantity weights to obtain shelf price indices and net price indices. For each of the commodities, regressions will be run using store-level product (UPC) weekly data. The reduced form regressions consist of projecting the shelf price index, as well as the net price index, (This abstract was borrowed from another version of this item.)