Timing and Quantity of Consumer Purchases and the Consumer Price Index
A common approach to measuring price changes is to look at the change of the expenditure needed to purchase a fixed basket of goods. It is well-known that this approach suffers from problems and creates several biases in the measurement of price changes faced by consumers. Substitution and outlet bias, two commonly studied concerns, are both driven by consumer choices of what and where to buy. However, consumers also make other choices, including how much and when to buy. We discuss the implications of consumers' timing and quantity decisions have on standard practices of computing of computing a price index. We use household-level data on quantities purchased and prices paid to construct a measure of the savings made by consumers' optimizing behaviour in the purchase of food. In particular, we compare the prices actually paid by the consumers to various alternatives that do not allow for substitution. Our analysis suggests that the average consumer makes significant, and comparable in magnitude, savings from the four dimensions of choice that we study. Furthermore, our data suggests significant heterogeneity in consumer behavior, and that this behavior is correlated with demographics. Our findings suggest that ignoring timing and quantity decisions, when computing a price index, can generate biases on the order of magnitude of substitution and outlet biases.
|Date of creation:||Oct 2008|
|Date of revision:|
|Note:||IO ME PR|
|Contact details of provider:|| Postal: National Bureau of Economic Research, 1050 Massachusetts Avenue Cambridge, MA 02138, U.S.A.|
Web page: http://www.nber.org
More information through EDIRC
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.:
- Christine Boizot & Jean-Marc Robin & Michael Visser, 2001.
"The Demand for Food Products: An Analysis of Interpurchase Times and Purchased Quantities,"
- Boizot, Christine & Robin, Jean-Marc & Visser, Michael, 2001. "The Demand for Food Products: An Analysis of Interpurchase Times and Purchased Quantities," Economic Journal, Royal Economic Society, vol. 111(470), pages 391-419, April.
- C, Boizot & Jean-Marc Robin & Michael Visser, 1997. "The Demand for Food Products : An Analysis of Interpurchase Times and Purchased Quantities," Working Papers 97-48, Centre de Recherche en Economie et Statistique.
- Baye, Michael R, 1985. "Price Dispersion and Functional Price Indices," Econometrica, Econometric Society, vol. 53(1), pages 213-23, January.
When requesting a correction, please mention this item's handle: RePEc:nbr:nberwo:14433. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: ()
If references are entirely missing, you can add them using this form.