American Economic Review: Vol. 99 No. 1 (March 2009)


Quick Tools:

Print Article Summary
Export Citation
Sign up for Email Alerts Follow us on Twitter


AER - All Issues

AER Forthcoming Articles

Peers at Work

Article Citation

Mas, Alexandre, and Enrico Moretti. 2009. "Peers at Work." American Economic Review, 99(1): 112-45.

DOI: 10.1257/aer.99.1.112


We study peer effects in the workplace. Specifically, we investigate whether, how, and why the productivity of a worker depends on the productivity of coworkers in the same team. Using high-frequency data on worker productivity from a large supermarket chain, we find strong evidence of positive productivity spillovers from the introduction of highly productive personnel into a shift. Worker effort is positively related to the productivity of workers who see him, but not workers who do not see him. Additionally, workers respond more to the presence of coworkers with whom they frequently interact. We conclude that social pressure can partially internalize free-riding externalities that are built into many workplaces. (JEL J24, L81, M54)

Article Full-Text Access

Full-text Article

Additional Materials

Download Data Set (64.68 KB)


Mas, Alexandre (U CA, Berkeley)
Moretti, Enrico (U CA, Berkeley)

JEL Classifications

J24: Human Capital; Skills; Occupational Choice; Labor Productivity
L81: Retail and Wholesale Trade; e-Commerce
M54: Personnel Economics: Labor Management

American Economic Review

Quick Tools:

Sign up for Email Alerts

Follow us on Twitter

Subscription Information
(Institutional Administrator Access)


AER - All Issues

AER - Forthcoming Articles

Virtual Field Journals

AEA Member Login:

AEAweb | AEA Journals | Contact Us