NATIONAL BUREAU OF ECONOMIC RESEARCH
NATIONAL BUREAU OF ECONOMIC RESEARCH

Measuring Ignorance in the Market: A New Method with an Application to Physician Services

Martin Gaynor, Solomon Polachek

NBER Working Paper No. 3430 (Also Reprint No. r1878)*
Issued in May 1994
NBER Program(s):   HE

The NBER Bulletin on Aging and Health provides summaries of publications like this.  You can sign up to receive the NBER Bulletin on Aging and Health by email.

Ever since Stigler's seninal piece on the econcinics of information, a

great deal of research has been done investigatirg equilibrium in markets

with imperfect imformation. While most of this research has been concerned

with theoretically establishing the conditions under which there exists a

distribution of prices in equilibrium, there is a small, but growing, body of

empirical research in this area.

This work has followed the sestion of Stigler ard utilized the

dispersion of prices (usually the variance) as a measure of ignorance about

price. There are two disadvantages to using the variance (or another measure

of dispersion, such as the range) of prices as a measure of ignorance about price. The first reason, recognized by Stigler ard others, is that price can

vary for many reasons other than ignorance. Thus dispersion is not a pure

measure of ignorance about prices. The second reason, which has not been

commonly considered in the empirical literature, is that price dispersion can due to ignorance on the part of both buyers and of sellers.

In this paper we propose a method for measuring ignorance about price in

a market which builds on Stigler's original suggestion to use dispersion as a

measure of ignorance. The innovation is to use a new frontier estiiation

technique containing a three component error term to separate observed price

dispersion into purely random variation, variation due to buyer ignorance,

and variation due to seller ignorance . We apply the technique to the

physicians' service market. This surplies us with quantitative indices of

price ignorance for different services and how the level of ignorance varies

by buyer, seller, and market area characteristics. The results are striking.

Buyer ignorance exceeds seller ignorance by roughly a factor of two in this

market, and this gap is greater for services which are less frequently

purchased, more heavily insured, or accompanied by greater severity of

illness, as predicted by search theory.

*Published: Southern Economic Journal, Volume 60(4), April 1994, pp. 815-831

You may purchase this paper on-line in .pdf format from SSRN.com ($5) for electronic delivery.

Information about Free Papers

You should expect a free download if you are a subscriber, a corporate associate of the NBER, a journalist, a site with your domain name in ".GOV", or a resident of nearly any developing country or transition economy.

If you usually get free papers at work/university but do not at home, you can either connect to your work VPN or proxy (if any) or elect to have a link to the paper emailed to your work email address below. The email address must be connected to a subscribing college, university, or other subscribing institution. Gmail and other free email addresses will not have access.

E-mail:

Machine-readable bibliographic record - MARC, RIS, BibTeX

 
Publications
Activities
Meetings
Data
People
About

National Bureau of Economic Research, 1050 Massachusetts Ave., Cambridge, MA 02138; 617-868-3900; email: info@nber.org