How Retail Beef and Bread Prices Respond to Changes in Ingredient and Input Costs
by Edward Roeger and
Ephraim LeibtagEconomic Research Report No. (ERR-112) 34 pp, February 2011
What Is the Issue?
Periodic spikes in the prices of major field crops and related
commodities such as those from 1971 to 1974, 1994 to 1996, and 2006
to 2008 have stimulated questions about how these shocks affect
wholesale and retail food prices. To what extent do wholesale food
prices respond to changes in the underlying costs of inputs? How
much of a change in input costs is passed through to retail prices
and how long does it take for such cost changes to pass
through?
Retail and wholesale prices will generally follow upstream
commodity prices directionally, but there are often factors that
limit this responsiveness. The extent to which price changes are
passed through depends on the value added by each producer in the
production process and a number of other organizational and
marketing factors at each stage of production, leading to input
price changes that are only partially reflected in later stages of
the supply chain, and, at times, a lack of measurable response in
the downstream product's price.
In this study, we develop price pass-through models for
farm-to-wholesale and wholesale-to-retail price changes using 36
years of monthly Bureau of Labor Statistics price indices data
(1972-2008). We focus on the wheat to retail bread and the cattle
to retail beef chains because they represent examples of supply
chains with significantly different degrees of processing between
stages.
What Were the Major Findings?
Pass-through rates and timing can vary dynamically between
prices at different stages in the supply chain, across food
categories, and for a given relationship over time.
• A more processed item (bread/wheat flour) showed less response
to upstream price changes than did a less processed item
(retail/wholesale beef).
- Retail beef prices typically incorporated between 19 to 29
percent of a change in the wholesale beef price after 6 months,
while wholesale beef prices incorporated 52 to 54 percent of the
change cattle prices.
- Retail bread prices typically incorporated 16 to 21 percent of
wholesale wheat flour price changes, while wholesale prices of
wheat flour incorporated 29 to 31 percent of changes in wheat
commodity prices.
• Wholesale prices for beef and wheat flour both responded in a
generally symmetric manner to changes in farm prices regardless of
the size and direction of change, while retail prices for both beef
and bread for which prices adjusted asymmetrically (especially in
more recent years), with the adjustment dependent upon the
characteristics of the wholesale price change.
• For both beef and bread, most of the change at the farm level
was passed on to the wholesale stage within the first month, with
some additional adjustments to the long-term equilibrium price
after that.
• Retail prices had a more complicated response to wholesale
price changes, and for both bread and beef, the passthrough from
wholesale to retail was weaker than the pass-through from farm to
wholesale. Retail price responses were strongest when wholesale
prices were relatively high. When prices were more stable or in
times of price declines, significant pass-through often did not
appear for several months.
How Was the Study Conducted?
We analyze the farm-to-wholesale and wholesale-to-retail price
relationships using a two-stage error correction model that allows
for the possibility of asymmetric price response. We also test for
structural breaks in the long-term (cointegrating) relationships.
Variations in the response of the downstream prices that are
dependent on the magnitude and/or sign of changes in the upstream
prices are modeled by considering a threshold-type response based
on the downstream price's position relative to the expected
long-term relationship.
This research extends the work of recent empirical studies that
have investigated the complexity of commodity passthrough
relationships using newly developed statistical tools. We
characterize price-response behavior in a manner that is not overly
influenced by any short-term market conditions that can dominate
samples of fewer years by including a long time period and
considering different possible types of asymmetric price
adjustment. Our models also allow more freedom for the
relationships between points in the supply chain to vary for a
given food group and include energy and labor variables as
short-term inputs.