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Do Robotic Calls from Credible Sources Influence Voter Turnout or Vote Choice?

Last registered on July 20, 2016

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Pre-Trial

Trial Information

General Information

Title

Do Robotic Calls from Credible Sources Influence Voter Turnout or Vote Choice?

RCT ID

AEARCTR-0001430

Initial registration date

July 20, 2016

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published

July 20, 2016, 12:36 PM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

Country

United States of America

Region

Primary Investigator

Name

Affiliation

Columbia University

Contact Primary Investigator

Other Primary Investigator(s)

PI Name

PI Affiliation

University of Texas at Austin

Contact Investigator

PI Name

PI Affiliation

Yale University

Contact Investigator

Additional Trial Information

Status

Completed

Start date

2003-03-06

End date

2003-03-08

Keywords

Additional Keywords

electoral participation

JEL code(s)

Secondary IDs

Abstract

The effectiveness of prerecorded phone calls was assessed in the context of a Texas Republican primary election that featured a contest for state Supreme Court. Automated calls endorsing one of the judicial candidates were recorded by the sitting Republican governor and directed at more than a quarter million people identified as likely voters and probably supporters of the governor. Two experimental designs were used to evaluate the calls' effectiveness. The first design randomly assigned households to treatment and control conditions in order to gauge the calls' effects on individuals' voter turnout, as measured by public records. The second design randomly assigned precincts to treatment and control conditions in order to assess whether the calls increased the precinct-level vote margin of the endorsed candidate. Results suggest that the automated calls had weak and statistically insignificant effects on turnout and vote margins.

External Link(s)

J-PAL Evaluation Summary

Registration Citation

Citation

Gerber, Alan, Donald Green and Daron Shaw. 2016. "Do Robotic Calls from Credible Sources Influence Voter Turnout or Vote Choice?." AEA RCT Registry. July 20. https://doi.org/10.1257/rct.1430-1.0

Former Citation

Gerber, Alan, Donald Green and Daron Shaw. 2016. "Do Robotic Calls from Credible Sources Influence Voter Turnout or Vote Choice?." AEA RCT Registry. July 20. https://www.socialscienceregistry.org/trials/1430/history/9492

Sponsors & Partners

Experimental Details

Interventions

Intervention(s)

Automated phone calls with the recorded voice of Governor Rick Perry urging Republicans to support a candidate for Texas Supreme Court.

Intervention Start Date

2003-03-06

Intervention End Date

2003-03-08

Primary Outcomes

Primary Outcomes (end points)

Effects of Robotic Calls on Voter Turnout Based on Precinct Level Random Assignment

- Percentage Voting

Effect of Robotic Calls on Voter Turnout Based on Household Level Random Assignment, by Household Size:

- One-Voter Households Percentage Voting

- Two-Voter Households Percentage Voting

Estimated Effects of Robotic Calls on Precinct-Level Outcomes:

- GOP Primary Votes Cast

- GOP Turnout

- Votes Cast for Willett or Smith

- Willett Votes

- Net Willett-Smith Difference

Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)

Secondary Outcomes (explanation)

Experimental Design

Experimental Design

This study consisted of a two-tiered experiment aimed at evaluating how automated phone calls affect both voter mobilization and persuasion. This evaluation was conducted in the context of a Texas Republican primary election that featured a contest for state Supreme Court. Automated calls endorsing one of the judicial candidates, Don Willett, were recorded by the sitting Republican governor, Rick Perry, and directed at more than a quarter million people identified as likely voters and probable supporters of the governor. The working hypothesis was that calls conveying a message from a prominent and credible source, such as the sitting Republican Governor, should have a persuasive effect.

The first experimental analysis randomly assigned precincts containing between 100 and 700 (likely) Republican and pro-Perry households to treatment and control groups. The turnout and persuasion hypotheses were assessed by comparing average outcomes in the treatment and control precincts.

The second analysis occurred in precincts containing fewer than 100 or more than 700 Republican households. Within these precincts, households, rather than precincts, were randomly assigned to treatment or control groups.

Experimental Design Details

Randomization Method

Experiment 1:

Turnout was measured at the level of the individual voter. Random assignment of targeted households was conducted using a random generator in SPSS.

Experiment 2:

Within the precincts selected for experiment 2, households, rather than precincts, were randomly assigned to treatment or control groups. Robotic calls were directed only to phone numbers belonging to individuals in the treatment group.

Randomization Unit

Experiment 1:

- Turnout measured at the level of the individual voter and assigned at the household level (where households were defined as shared phone numbers)

- Vote choice observed at the precinct level

Experiment 2:

Precincts were assigned to treatment or control using the same targeting criteria as the household-level random assignment. Turnout and vote choice observed at the household level

Was the treatment clustered?

Yes

Experiment Characteristics

Sample size: planned number of clusters

1,597 precincts

Sample size: planned number of observations

292,602 voters

Sample size (or number of clusters) by treatment arms

Experiment 1:

- The 815 treatment precincts contained a total of 147,660 voters, as compared to 782 control precincts, which contained 144,942 voters. Vote choice was observed only at the precinct level.

Experiment 2:

- A total of 105,270 voters lived in households whose phone number was assigned to the treatment group. The control group comprised 65,657 voters.

Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Supporting Documents and Materials

Institutional Review Boards (IRBs)

IRB Name

IRB Approval Date

IRB Approval Number

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?

Yes

Intervention Completion Date

March 08, 2003, 12:00 +00:00

Data Collection Complete

Yes

Data Collection Completion Date

March 08, 2003, 12:00 +00:00

Final Sample Size: Number of Clusters (Unit of Randomization)

1,597 precincts

Was attrition correlated with treatment status?

No

Final Sample Size: Total Number of Observations

292,602 voters

Final Sample Size (or Number of Clusters) by Treatment Arms

Experiment 1: - The 815 treatment precincts contained a total of 147,660 voters, as compared to 782 control precincts, which contained 144,942 voters. Vote choice was observed only at the precinct level. Experiment 2: - A total of 105,270 voters lived in households whose phone number was assigned to the treatment group. The control group comprised 65,657 voters.

Data Publication

Data Publication

Is public data available?

Yes

Public Data URL

http://isps.yale.edu/research/data/d044#.V4qP_5MrKYV

Program Files

Program Files

No

Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials