Baseline, Placebo, and Treatment: Efficient Estimation for Three-Group Experiments

Author(s): 

Gerber, Alan S., Donald P. Green, Edward H. Kaplan and Holger L. Kern

ISPS ID: 
ISPS10-020
Full citation: 
Gerber, Alan S., Donald P. Green, Edward H. Kaplan and Holger L. Kern (2010) "Baseline, Placebo, and Treatment: Efficient Estimation for Three-Group Experiments." Political Analysis 18(3): 297-315.
Abstract: 
Randomized experiments commonly compare subjects receiving a treatment to subjects receiving a placebo. An alternative design, frequently used in field experimentation, compares subjects assigned to an untreated baseline group to subjects assigned to a treatment group, adjusting statistically for the fact that some members of the treatment group may fail to receive the treatment. This article shows the potential advantages of a three-group design (baseline, placebo, and treatment). We present a maximum likelihood estimator of the treatment effect for this three-group design and illustrate its use with a field experiment that gauges the effect of prerecorded phone calls on voter turnout. The three-group design offers efficiency advantages over two-group designs while at the same time guarding against unanticipated placebo effects (which would undermine the placebo-treatment comparison) and unexpectedly low rates of compliance with the treatment assignment (which would undermine the baseline-treatment comparison).
Attachments: 
https://isps.yale.edu/sites/default/files/publication/2012/12/ISPS10-020.pdf
Supplemental information: 

Link to article here.

Location: 
Location details: 
Michigan
Publication date: 
2010
Publication type: 
Publication name: 
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