IDEAS home Printed from
   My bibliography  Save this paper

Unobservable Product Differentiation in Discrete Choice Models: Estimating Price Elasticities and Welfare Effects


  • Daniel A. Ackerberg
  • Marc Rysman

    (Boston University)


Discrete choice models used in statistical applications typically interpret an unobservable term as the interaction of unobservable horizontal differentiation and idiosyncratic consumer preferences. An implicit assumption in most such models is that all choices are equally horizontally differentiated from each other. This assumption is problematic in a number of recent studies that use discrete choice frameworks to evaluate the welfare effects from different numbers of goods (e.g. Berry and Waldfogel, 1999; Rysman, 2000). Researchers might think that it is possible for product space to "fill up" and that ignoring this issue might lead to an overestimate of welfare as the number of new products increases. This paper proposes a solution whereby the researcher estimates the decrease in value that agents receive from higher numbers of products as a result of the decreasing importance of horizontal differentiation. The paper reviews previous results on how a linear random utility model (LRUM) can be mapped into an address (Hotelling) model. The paper shows how realistic assumptions on differentiation in an address setting can be mapped into an LRUM. LRUM models imply that all choices are strong gross substitutes. In order to preserve that condition in an address model, n choices must be differentiated along at least $n-1$ dimensions. This paper proposes that utility drawn from different dimensions be weighted differently. Mapping this feature into an LRUM requires weighting the utility from each choice based upon the dimension along which it is differentiated from others. As researchers will typically be unwilling to make assumptions about which dimension products differ on, the paper discusses integrating over the different possibilities in a computationally inexpensive way that still allows the researcher to relax the assumption of symmetric differentiation.

Suggested Citation

  • Daniel A. Ackerberg & Marc Rysman, 2000. "Unobservable Product Differentiation in Discrete Choice Models: Estimating Price Elasticities and Welfare Effects," Econometric Society World Congress 2000 Contributed Papers 1675, Econometric Society.
  • Handle: RePEc:ecm:wc2000:1675

    Download full text from publisher

    File URL:
    File Function: main text
    Download Restriction: no

    References listed on IDEAS

    1. Steven T. Berry & Joel Waldfogel, 1999. "Free Entry and Social Inefficiency in Radio Broadcasting," RAND Journal of Economics, The RAND Corporation, vol. 30(3), pages 397-420, Autumn.
    2. Marc Rysman, 2004. "Competition Between Networks: A Study of the Market for Yellow Pages," Review of Economic Studies, Oxford University Press, vol. 71(2), pages 483-512.
    Full references (including those not matched with items on IDEAS)


    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.

    Cited by:

    1. Gautam Gowrisankaran & Marc Rysman, 2012. "Dynamics of Consumer Demand for New Durable Goods," Journal of Political Economy, University of Chicago Press, vol. 120(6), pages 1173-1219.
    2. Philip A. Haile & Ali Horta├žsu & Grigory Kosenok, 2008. "On the Empirical Content of Quantal Response Equilibrium," American Economic Review, American Economic Association, vol. 98(1), pages 180-200, March.
    3. Marc Rysman & Gautam Gowrisankaran & Minsoo Park, 2011. "Measuring Network Effects in a Dynamic Environment," Boston University - Department of Economics - Working Papers Series WP2011-061, Boston University - Department of Economics.

    More about this item


    Access and download statistics


    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:ecm:wc2000:1675. 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: (Christopher F. Baum). General contact details of provider: .

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service hosted by the Research Division of the Federal Reserve Bank of St. Louis . RePEc uses bibliographic data supplied by the respective publishers.