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, on commodity prices, other explanatory variables and on region and time dummies. The point estimates measure the effect of residual changes in commodity prices, net of seasonal and regional effects, on the prices consumers face when making purchase decisions. We also construct a variable that measures the frequency of price discounts and relate that variable to the same explanatory variables. We estimate pass through behavior using the above three different measures of retail price activity controlling for cost proxies, store-level fixed-effects and regional time trends using panel data estimation techniques. Results suggest that an important part of retail price variation comes from promotional activities, and the usual shelf price index would underestimate the true pass through coefficient. To deal with omitted variables and price stickiness we included a lagged dependent variable, using the Arellano-Bond dynamic panel estimator. For Chicken the results show that using standard information on regular shelf price leads to an underestimation of the true pass-through coefficient. For Cereal, using standard shelf prices leads to an overestimation of the pass-through coefficient reflecting the importance of storability faced by consumers and retailers, and industry characteristics in the sale dynamics. Not only do our cost pass-through estimates account for sales we also provide dynamic multipliers for grain commodity price increases to supermarket shelf prices. The estimated dynamic elasticities are not as small as one might expect from a naive model. The elasticity of cereal price with respect to flour is over 1 and the elasticity of chicken price with respect to chicken feed was 30 percent. These estimates would imply a very large price increase in cereal and chicken over the last several years. There are fewer sales when commodity prices go up. From this we would conclude that net prices should be used for pass-through analysis.
|Date of creation:||16 Jun 2009|
|Contact details of provider:|| Postal: 207 Giannini Hall #3310, Berkeley, CA 94720-3310|
Phone: (510) 642-3345
Fax: (510) 643-8911
Web page: http://www.escholarship.org/repec/are_ucb/
More information through EDIRC
References listed on IDEAS
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
- Daniel Hosken & David Reiffen, 2004. "Patterns of Retail Price Variation," RAND Journal of Economics, The RAND Corporation, vol. 35(1), pages 128-146, Spring.
- Bruce L. Gardner, 1975. "The Farm-Retail Price Spread in a Competitive Food Industry," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 57(3), pages 399-409.
- Igal Hendel & Aviv Nevo, 2006.
"Measuring the Implications of Sales and Consumer Inventory Behavior,"
Econometric Society, vol. 74(6), pages 1637-1673, November.
- Igal Hendel & Aviv Nevo, 2005. "Measuring the Implications of Sales and Consumer Inventory Behavior," NBER Working Papers 11307, National Bureau of Economic Research, Inc.
- Dale M. Heien, 1980. "Markup Pricing in a Dynamic Model of the Food Industry," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 62(1), pages 10-18.
- Dora Gicheva & Justine Hastings & Sofia Villas-Boas, 2007. "Revisiting the Income Effect: Gasoline Prices and Grocery Purchases," NBER Working Papers 13614, National Bureau of Economic Research, Inc.
- Gicheva, Dora & Hastings, Justine & Villas-Boas, Sofia B, 2008. "Revisiting the Income Effect: Gasoline Prices and Grocery Purchases," Department of Agricultural & Resource Economics, UC Berkeley, Working Paper Series qt7087m1p6, Department of Agricultural & Resource Economics, UC Berkeley.
- Villas-Boas, Sofia B & Gicheva, Dora & Hastings, Justine, 2010. "Revisiting the Income Effect: Gasoline Prices and Grocery Purchases," Department of Agricultural & Resource Economics, UC Berkeley, Working Paper Series qt8448m75z, Department of Agricultural & Resource Economics, UC Berkeley.
- Berck, Peter & Brown, Jennifer & Perloff, Jeffrey M. & Villas-Boas, Sofia Berto, 2008. "Sales: Tests of theories on causality and timing," International Journal of Industrial Organization, Elsevier, vol. 26(6), pages 1257-1273, November.
- Berck, Peter & Brown, Jennifer & Perloff, Jeffrey M & Villas-Boas, Sofia B., 2007. "Sales: Tests of Theories on Causality and Timing," Department of Agricultural & Resource Economics, UC Berkeley, Working Paper Series qt2g56n1jk, Department of Agricultural & Resource Economics, UC Berkeley.
- Villas-Boas, Sofia B & Perloff, Jeff & Berck, Peter & Brown, Jen, 2008. "Sales: Tests of Theories on Causality and Timing," Department of Agricultural & Resource Economics, UC Berkeley, Working Paper Series qt0076k5r6, Department of Agricultural & Resource Economics, UC Berkeley.
- Leibtag, Ephraim S. & Nakamura, Alice & Nakamura, Emi & Zerom, Dawit, 2007. "Cost Pass-Through In The U.S. Coffee Industry," Economic Research Report 7253, United States Department of Agriculture, Economic Research Service.
- Nevo, Aviv, 2001. "Measuring Market Power in the Ready-to-Eat Cereal Industry," Econometrica, Econometric Society, vol. 69(2), pages 307-342, March.
- Nevo, Aviv, 1998. "Measuring Market Power in the Ready-To-Eat Cereal Industry," Food Marketing Policy Center Research Reports 037, University of Connecticut, Department of Agricultural and Resource Economics, Charles J. Zwick Center for Food and Resource Policy.
- Nevo, Aviv, 1999. "Measuring Market Power in the Ready-to-Eat Cereal Industry," Competition Policy Center, Working Paper Series qt7cm5p858, Competition Policy Center, Institute for Business and Economic Research, UC Berkeley.
- Aviv Nevo, 2003. "Measuring Market Power in the Ready-to-Eat Cereal Industry," Microeconomics 0303006, EconWPA.
- Nevo, Aviv, 1998. "Measuring Market Power in the Ready-To-Eat Cereal Industry," Research Reports 25164, University of Connecticut, Food Marketing Policy Center.
- Aviv Nevo, 1998. "Measuring Market Power in the Ready-to-Eat Cereal Industry," NBER Working Papers 6387, National Bureau of Economic Research, Inc.
- Christian Rojas & Alexandra Andino & Wayne D. Purcell, 2008. "Retailers' response to wholesale price changes: new evidence from scanner-based quantity-weighted beef prices," Agribusiness, John Wiley & Sons, Ltd., vol. 24(1), pages 1-15.
- Martin Pesendorfer, 2002. "Retail Sales: A Study of Pricing Behavior in Supermarkets," The Journal of Business, University of Chicago Press, vol. 75(1), pages 33-66, January.
- Manuel Arellano & Stephen Bond, 1991. "Some Tests of Specification for Panel Data: Monte Carlo Evidence and an Application to Employment Equations," Review of Economic Studies, Oxford University Press, vol. 58(2), pages 277-297.
- Tom Doan, "undated". "RATS program to replicate Arellano-Bond 1991 dynamic panel," Statistical Software Components RTZ00169, Boston College Department of Economics.
- Levin, Andrew & Lin, Chien-Fu & James Chu, Chia-Shang, 2002. "Unit root tests in panel data: asymptotic and finite-sample properties," Journal of Econometrics, Elsevier, vol. 108(1), pages 1-24, May.
- Tom Doan, "undated". "LEVINLIN: RATS procedure to perform Levin-Lin-Chu test for unit roots in panel data," Statistical Software Components RTS00242, Boston College Department of Economics.