Garrett Johnson

Associate Professor of Marketing at Boston University Questrom School of Business

Empirical research on digital advertising effectiveness and the economics of online ad markets

Thought LeaderBoston, Massachusetts, United States12+ years in industry

Last updated Jun 6, 2026 by the ATDb Editorial Team

Bio

Garrett Johnson is an Associate Professor of Marketing at Boston University Questrom School of Business, where he researches the economics of digital advertising with a focus on empirical questions around ad effectiveness, incrementality, and market structure. He joined Questrom as an Assistant Professor in 2015 after completing his doctoral research at the University of Rochester Simon Business School.

Previous Roles

Assistant Professor

Boston University Questrom School of Business (2015-2021)

Doctoral Researcher

University of Rochester Simon Business School (2010-2015)

Expertise

Advertising Measurement & IncrementalityDigital Advertising EconomicsProgrammatic AdvertisingAd FraudPrivacy and Identity in AdvertisingPlatform EconomicsCausal Inference in MarketingAttribution Modeling

Education

PhD, Business Administration (Marketing), University of Rochester Simon Business School
BA, Economics, Dartmouth College

Notable Achievements

Published widely-cited research demonstrating the limited incrementality of retargeting advertising, influencing industry debates on attribution
Produced empirical studies on ad fraud economics that quantified the scale and incentive structures enabling invalid traffic
Research on cookie-based tracking and its role in advertising market structure cited in privacy policy discussions
Recipient of research grants and awards from the Marketing Science Institute for work on digital advertising effectiveness

Awards

Marketing Science Institute Research Grant recipientBest Paper recognition in marketing and economics academic venues

Speaking Topics

Incrementality and causal measurement in digital advertisingEconomics of ad fraud and invalid trafficPrivacy regulation and its impact on advertising marketsPlatform competition and programmatic market structureCookie deprecation and identity resolution challenges

Publications

Johnson, G. A., Lewis, R. A., & Reiley, D. H. — 'When Less is More: Data and Power in Advertising Experiments'
Johnson, G. A. — 'The Impact of Privacy Policy on the Auction Market for Online Display Advertising'
Johnson, G. A., Shriver, S. K., & Du, S. — 'Consumer Privacy Choice in Online Advertising'
Johnson, G. A. — 'Regulating Privacy Online: An Economic Evaluation of the GDPR'