More than a Penny's Worth: Left-Digit Bias and Firm Pricing

79 Pages Posted: 2 Jul 2019 Last revised: 4 Dec 2019

See all articles by Avner Strulov-Shlain

Avner Strulov-Shlain

University of Chicago - Booth School of Business

Date Written: June 3, 2019


Firms arguably price at 99-ending prices because of left-digit bias, the tendency of consumers
to perceive a $4.99 as much lower than $5.00. Using retail scanner data on thousands of products
and dozens of retailers, I provide reduced-form support for this explanation. I then structurally
estimate the magnitude of left-digit bias, and find that consumers respond to a 1-cent increase
from a 99-ending price as if it were a 15-25 cent increase. Next, I analyze how firms should
respond to left-digit biased demand. I solve and estimate a model that makes three key predictions:
(1) prices should bunch at 99-ending prices; (2) there should be ranges of missing prices
with low price-endings; (3) these ranges of missing prices should increase with the dollar digit.
Qualitatively, these predictions hold. Firms respond to the bias with high shares of 99s and
missing low-ending prices. Quantitatively, however, firms price as if the bias were much smaller
and demand were more elastic, so they use dominated prices. I estimate that the retailer is
forgoing 1-3 percents of potential gross profits due to this misperception.

JEL Classification: D90, D12, D22, L11, L20, L81

Suggested Citation

Strulov-Shlain, Avner, More than a Penny's Worth: Left-Digit Bias and Firm Pricing (June 3, 2019). Chicago Booth Research Paper No. 19-22, Available at SSRN: or

Avner Strulov-Shlain (Contact Author)

University of Chicago - Booth School of Business ( email )

5807 S. Woodlawn Avenue
Chicago, IL 60637
United States

Do you have a job opening that you would like to promote on SSRN?

Paper statistics

Abstract Views
PlumX Metrics