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)
| Reference | Where | Use in the paper | Vault note |
|---|---|---|---|
| Coen, R. (2008), Coen Structured Advertising Expenditure Dataset | p. 1941 | Source, with Kantar, for US ad spend of about $500 per person per year | Lewis Rao 2015 - Unfavorable Economics of Ad Measurement - Overview |
| Kantar Media (2012), Kantar AdSpender | p. 1941; p. 1967 | Second 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 spending | Overview; 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 68 | p. 1941 | Cited 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 volume | p. 1942, fn. 2; p. 1955 | Fuller 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:
| Reference | Setting named in fn. 18 |
|---|---|
| Carroll, V., Rao, A., Lee, H., Shapiro, A. & Bayus, B. (1985), “The Navy Enlistment Marketing Experiment,” Marketing Science 4 | Enlistment (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 32 | TV commercials for retailers |
| Joo, M., Wilbur, K., Cowgill, B. & Zhu, Y. (2013), “Television Advertising and Online Search,” Management Science 60 | TV commercials for retailers |
| Eastlack, J., Jr. & Rao, A. (1989), “Advertising Experiments at the Campbell Soup Company,” Marketing Science 8 | Various 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 Conference | Online ads |
| Lewis, R. A. & Reiley, D. H. (2014), “Online Ads and Offline Sales,” Quantitative Marketing and Economics 12 | Online 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)
| Reference | Where | Use in the paper | Vault note |
|---|---|---|---|
| Cohen, J. (1977), Statistical Power Analysis for the Behavioral Sciences | p. 1950, fns. 9-10 | The 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 0.2 | Lewis 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 39 | p. 1950 | Reference 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 18 | p. 1951, fn. 11 | Their low-powered store-level examples have around 6%, more than 10,000 times the user-level here | Impact-to-SD note |
| Card, D. (1999), “The Causal Effect of Education on Earnings,” Handbook of Labor Economics 3 | p. 1951 | Comparison: 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 larger | Impact-to-SD note |
| Abraham, M. (2008), “The Off-Line Impact of Online Ads,” Harvard Business Review 86 | p. 1952 | The comScore-style 300% effect from comparing exposed and unexposed users, which would imply ad prices at least ten times higher | Impact-to-SD note; Experimental Benchmarks for Observational Ad Measurement |
| Blake, T., Nosko, C. & Tadelis, S. (2014), “Consumer Heterogeneity and Paid Search Effectiveness,” NBER WP 20171 | p. 1952; p. 1967 | Industry use of observational methods; the one large experiment that changed an advertiser’s (eBay’s) strategy | Blake Nosko Tadelis 2015 - Paid Search Effectiveness - Overview |
| Gelman, A. & Carlin, J. (2013), “Beyond Power Calculations,” working paper | p. 1951; p. 1952 | The “exaggeration factor” of low-powered tests; one reason point estimates are withheld | Type 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,” WSDM | p. 1957; p. 1969 | Variance reductions from pre-period covariates match related work; future ad servers could include pre-experiment matching | Lewis 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 paper | p. 1956 | For “buy it now or never” response patterns, the bias from short evaluation windows is minimal | Table II note |
| Bagwell, K. (2007), “The Economic Analysis of Advertising,” Handbook of Industrial Organization 3 | p. 1963 | Most ad-effectiveness papers test whether the sales effect differs from zero | Lewis Rao 2015 - Table III Power and Experiment Size Multipliers |
4. The Yahoo! experiments and their predecessors (§II.A, §III.A-B)
| Reference | Where | Use in the paper |
|---|---|---|
| Lewis, R. A. (2010), Where’s the “Wear-Out?”, MIT PhD dissertation | p. 1946, fn. 7 | Evidence for concave ad response (with Sahni 2013) |
| Sahni, N. (2013), “Effect of Temporal Spacing between Advertising Exposures,” Stanford GSB WP | p. 1946, fn. 7 | Evidence for concavity |
| Lewis, R. A. & Schreiner, T. A. (2010), “Can Online Display Advertising Attract New Customers?,” MIT thesis | p. 1954 | Design 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. 18 | Realistic 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,” unpublished | p. 1954, fn. 13 | Source of some of the 25 experiments |
| Johnson, G., Lewis, R. A. & Reiley, D. H. (2015), “Location, Location, Location,” SSRN WP 2268215 | p. 1954, fn. 13; p. 1959; p. 1965, fn. 21 | Source 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. 13 | Correlation 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)
| Reference | Where | Use in the paper | Vault note |
|---|---|---|---|
| Kaiser, H. (2005), Economics of Commodity Promotion Programs | p. 1948, fn. 8 | Homogeneous foodstuffs have stable spending, but ad spillovers to competitors reduce own-firm returns | Impact-to-SD note |
| de Bartolome, C. (1995), “Which Tax Rate Do People Use: Average or Marginal?,” Journal of Public Economics 56 | p. 1965 | Decision makers may confuse average and marginal returns in the over-advertising region | Lewis 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 128 | p. 1945; p. 1965; p. 1971 | Consulting 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 counterfactual | Lewis 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 36 | p. 1966 | Voting as a category with volatile outcomes | Robustness note |
| Shin, H. S. (1994), “News Management and the Value of Firms,” RAND Journal of Economics 25 | p. 1970 | The persuasion-game model applied to media buyers | Market Implications note |
| Lee, I-M. et al. (2005), “Vitamin E in the Primary Prevention of Cardiovascular Disease and Cancer,” JAMA 294 | p. 1971, fn. 28 | Physicians Health Study II: 39,876 women, 12 years, inconclusive 95% CI | Market 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
- Power Analysis and Sample Size and Type S and Type M Errors — the generic theory behind the Cohen, Sawyer & Ball and Gelman & Carlin citations.
- CUPED and Regression-Adjusted Variance Reduction — the method family of Deng et al. (2013).
- Blake Nosko Tadelis 2015 - Paid Search Effectiveness - Overview — the published version of the eBay working paper.
See Also
- Lewis Rao 2015 - Unfavorable Economics of Ad Measurement - Overview — paper map and Source Map.
- The Unfavorable Economics of Ad Experiments - Power and Signal-to-Noise — synthesis across this and related Yahoo! papers.
- Gordon et al 2019 - Reference List and Cited Literature — sibling bibliography