Lewis Rao 2015 - Reference List and Cited Literature

Summary

The paper’s reference list (pp. 1972-1973) has 31 works. This note lists every one, with the page and the purpose for which Lewis & Rao cite it, and the vault note that discusses that passage. Grouped by role: framing the question, earlier ad field experiments, statistical method, the Yahoo! experiments themselves, robustness examples, and market implications. Page numbers come from the running heads of the raw PDF. A footnote is assigned to the page whose foot it sits on.

Overview

Most references are used once, to support a single claim. Four clusters matter for reading the paper:

  • Yahoo! Labs predecessors (fn. 13): many of the 25 experiments were first analyzed in earlier papers by the same group.
  • Field-experiment precedents (fn. 18): earlier randomized ad tests in recruiting, TV, packaged foods and online display.
  • Power and design-analysis literature (Cohen; Sawyer & Ball; Gelman & Carlin): calibrates how small the ad effect is.
  • Analogies for the market argument (Bloom et al.; Lee et al.; Shin): other markets with poorly measured returns, and the persuasion-game model.

Main Content

1. Framing the question (§I)

ReferenceWhereUse in the paperVault note
Coen, R. (2008), Coen Structured Advertising Expenditure Datasetp. 1941Source, with Kantar, for US ad spend of about $500 per person per yearLewis Rao 2015 - Unfavorable Economics of Ad Measurement - Overview
Kantar Media (2012), Kantar AdSpenderp. 1941; p. 1967Second source for the $500 figure; in §IV.A, Kantar AdSpender and other industry sources support the claim that large, publicly traded advertisers using standard ad formats account for most ad spendingOverview; Lewis Rao 2015 - Robustness, Scale, Targeting and Measurement Technology
Abraham, M. & Lodish, L. (1990), “Getting the Most out of Advertising and Promotion,” Harvard Business Review 68p. 1941Cited for the open question: does advertising affect purchases as much as ad prices and gross margins imply?Overview
Lewis, R. A., Rao, J. M. & Reiley, D. H. (2015), “Measuring the Effects of Advertising: The Digital Frontier,” NBER volumep. 1942, fn. 2; p. 1955Fuller treatment of the complications from intermediate metrics such as clicks; proof of the evaluation-window proposition (an extra week helps only if its effect exceeds half the running average)Lewis Rao 2015 - Impact-to-SD Ratio Derivation and Calibrated Campaign

2. Earlier advertising field experiments (fn. 18, p. 1963)

Footnote 18 supports the statement that most ad-effectiveness papers test whether the causal effect on sales differs from zero (Bagwell 2007). It lists specific field experiments:

ReferenceSetting named in fn. 18
Carroll, V., Rao, A., Lee, H., Shapiro, A. & Bayus, B. (1985), “The Navy Enlistment Marketing Experiment,” Marketing Science 4Enlistment (military recruiting) advertising
Lodish, L., Abraham, M., Kalmenson, S., Livelsberger, J., Lubetkin, B., Richardson, B. & Stevens, M. E. (1995), “How TV Advertising Works: A Meta-Analysis of 389 Real World Split Cable TV Advertising Experiments,” Journal of Marketing Research 32TV commercials for retailers
Joo, M., Wilbur, K., Cowgill, B. & Zhu, Y. (2013), “Television Advertising and Online Search,” Management Science 60TV commercials for retailers
Eastlack, J., Jr. & Rao, A. (1989), “Advertising Experiments at the Campbell Soup Company,” Marketing Science 8Various media for packaged foods
Reiley, D. H., Rao, J. M. & Lewis, R. A. (2011), “Here, There, and Everywhere: Correlated Online Behaviors Can Lead to Overestimates of the Effects of Advertising,” WWW ConferenceOnline ads
Lewis, R. A. & Reiley, D. H. (2014), “Online Ads and Offline Sales,” Quantitative Marketing and Economics 12Online ads

The split-cable TV meta-analysis (Lodish et al. 1995) is the classic aggregate precedent. TV ads were randomized by household cable feed, which is the same idea as the user-level display tests here. See User-Level vs Geo-Level Experiments - When to Use Which and Geo-Experiment Design and Power Analysis for the geographic alternative that fn. 6 calls more expensive.

3. Statistical method and power (§II.B, §III)

ReferenceWhereUse in the paperVault note
Cohen, J. (1977), Statistical Power Analysis for the Behavioral Sciencesp. 1950, fns. 9-10The impact-to-s.d. ratio “is also known as Cohen’s d”; the calibrated ratio is less than 1/40 of Cohen’s “small” effect size of 0.2Lewis Rao 2015 - Impact-to-SD Ratio Derivation and Calibrated Campaign; Power Analysis and Sample Size
Lovell, M. (2008), “A Simple Proof of the FWL Theorem,” Journal of Economic Education 39p. 1950Reference for the Frisch-Waugh-Lovell algebra behind the partial after conditioning on covariates (§II.B)Impact-to-SD note
Sawyer, A. & Ball, A. D. (1981), “Statistical Power and Effect Size in Marketing Research,” Journal of Marketing Research 18p. 1951, fn. 11Their low-powered store-level examples have around 6%, more than 10,000 times the user-level hereImpact-to-SD note
Card, D. (1999), “The Causal Effect of Education on Earnings,” Handbook of Labor Economics 3p. 1951Comparison: in returns-to-schooling work, the bias from omitted variables is thought to be 10-30% of the treatment effect, while in advertising it can be many times largerImpact-to-SD note
Abraham, M. (2008), “The Off-Line Impact of Online Ads,” Harvard Business Review 86p. 1952The comScore-style 300% effect from comparing exposed and unexposed users, which would imply ad prices at least ten times higherImpact-to-SD note; Experimental Benchmarks for Observational Ad Measurement
Blake, T., Nosko, C. & Tadelis, S. (2014), “Consumer Heterogeneity and Paid Search Effectiveness,” NBER WP 20171p. 1952; p. 1967Industry use of observational methods; the one large experiment that changed an advertiser’s (eBay’s) strategyBlake Nosko Tadelis 2015 - Paid Search Effectiveness - Overview
Gelman, A. & Carlin, J. (2013), “Beyond Power Calculations,” working paperp. 1951; p. 1952The “exaggeration factor” of low-powered tests; one reason point estimates are withheldType S and Type M Errors; Lewis Rao 2015 - Table I Summary of the 25 Yahoo Display Experiments
Deng, A., Xu, Y., Kohavi, R. & Walker, T. (2013), “Improving the Sensitivity of Online Controlled Experiments by Utilizing Pre-Experiment Data,” WSDMp. 1957; p. 1969Variance reductions from pre-period covariates match related work; future ad servers could include pre-experiment matchingLewis Rao 2015 - Table II Estimation Protocol, Windows and ROI Standard Errors; CUPED and Regression-Adjusted Variance Reduction
Damgaard, M. & Gravert, C. (2014), “Now or Never! The Effect of Deadlines on Charitable Giving,” working paperp. 1956For “buy it now or never” response patterns, the bias from short evaluation windows is minimalTable II note
Bagwell, K. (2007), “The Economic Analysis of Advertising,” Handbook of Industrial Organization 3p. 1963Most ad-effectiveness papers test whether the sales effect differs from zeroLewis Rao 2015 - Table III Power and Experiment Size Multipliers

4. The Yahoo! experiments and their predecessors (§II.A, §III.A-B)

ReferenceWhereUse in the paper
Lewis, R. A. (2010), Where’s the “Wear-Out?”, MIT PhD dissertationp. 1946, fn. 7Evidence for concave ad response (with Sahni 2013)
Sahni, N. (2013), “Effect of Temporal Spacing between Advertising Exposures,” Stanford GSB WPp. 1946, fn. 7Evidence for concavity
Lewis, R. A. & Schreiner, T. A. (2010), “Can Online Display Advertising Attract New Customers?,” MIT thesisp. 1954Design of hold-out vs charity-ad controls, where the size of the would-be-exposed control is unknown
Lewis & Reiley (2014)p. 1944, fn. 5; p. 1954, fn. 13; p. 1959; p. 1963, fn. 18Realistic targeting gap (10 percentage points) in the 30x selection example; source experiment; effects through basket size
Reiley, D. H., Lewis, R. A. & Schreiner, T. (2012), “Ad Attributes and Attribution,” unpublishedp. 1954, fn. 13Source of some of the 25 experiments
Johnson, G., Lewis, R. A. & Reiley, D. H. (2015), “Location, Location, Location,” SSRN WP 2268215p. 1954, fn. 13; p. 1959; p. 1965, fn. 21Source experiment; effects through purchase frequency; example of a multi-cell experiment that exogenously varies cost per person, used to trace (§III.D)
Reiley, Rao & Lewis (2011)p. 1951; p. 1954, fn. 13Correlation over time between ad exposure (web browsing) and shopping can generate an near 0.0001, a full order of magnitude larger than the true treatment effect; also a source experiment

Notes for these rows: Lewis Rao 2015 - The Advertiser’s Problem and Marginal ROI (fn. 7), Lewis Rao 2015 - Table I Summary of the 25 Yahoo Display Experiments (fn. 13, Schreiner), Lewis Rao 2015 - Table II Estimation Protocol, Windows and ROI Standard Errors (p. 1959 channels). Related design notes: Intent-to-Treat, PSA and Ghost Ad Designs.

5. Robustness, ROI targets and market implications (§III.C-§V)

ReferenceWhereUse in the paperVault note
Kaiser, H. (2005), Economics of Commodity Promotion Programsp. 1948, fn. 8Homogeneous foodstuffs have stable spending, but ad spillovers to competitors reduce own-firm returnsImpact-to-SD note
de Bartolome, C. (1995), “Which Tax Rate Do People Use: Average or Marginal?,” Journal of Public Economics 56p. 1965Decision makers may confuse average and marginal returns in the over-advertising regionLewis Rao 2015 - The Advertiser’s Problem and Marginal ROI
Bloom, N., Eifert, B., Mahajan, A., McKenzie, D. & Roberts, J. (2013), “Does Management Matter? Evidence from India,” QJE 128p. 1945; p. 1965; p. 1971Consulting as another hard-to-measure investment (§I); in §III.C, the first RCT of consulting found a positive effect but no precise ROI; in §V, consulting spending rarely has a well-formed counterfactualLewis Rao 2015 - Market Implications, Persuasion Games and Conclusion; Table III note
Broockman, D. & Green, D. (2014), “Do Online Advertisements Increase Political Candidates’ Name Recognition or Favorability?,” Political Behavior 36p. 1966Voting as a category with volatile outcomesRobustness note
Shin, H. S. (1994), “News Management and the Value of Firms,” RAND Journal of Economics 25p. 1970The persuasion-game model applied to media buyersMarket Implications note
Lee, I-M. et al. (2005), “Vitamin E in the Primary Prevention of Cardiovascular Disease and Cancer,” JAMA 294p. 1971, fn. 28Physicians Health Study II: 39,876 women, 12 years, inconclusive 95% CIMarket Implications note

Examples

Example: Checking a citation's arithmetic (Sawyer & Ball 1981, fn. 11)

Footnote 11 says the calibrated campaign’s of 0.0000054 is “less than 1/10,000” of the roughly 6% in Sawyer & Ball’s low-powered store-level examples. Check: , so the claim holds. The paper also notes their examples are aggregate store-level rather than customer-level models, which is why their is so much larger. See Lewis Rao 2015 - Impact-to-SD Ratio Derivation and Calibrated Campaign.

Connections

See Also