Does the Media Matter? A Field Experiment Measuring the Effect of Newspapers on Voting Behavior and Political Opinions
Last registered on July 26, 2016

Pre-Trial

Trial Information
General Information
Title
Does the Media Matter? A Field Experiment Measuring the Effect of Newspapers on Voting Behavior and Political Opinions
RCT ID
AEARCTR-0001128
Initial registration date
July 26, 2016
Last updated
July 26, 2016 2:35 PM EDT
Location(s)
Primary Investigator
Affiliation
Northwestern University
Other Primary Investigator(s)
PI Affiliation
Department of Communications, Michigan State University
Additional Trial Information
Status
Completed
Start date
2005-09-01
End date
2006-12-31
Secondary IDs
Abstract
We conducted a field experiment to measure the effect of exposure to newspapers on political behavior and opinion. Before the 2005 Virginia gubernatorial election, we randomly assigned individuals to a Washington Post free subscription treatment, a Washington Times free subscription treatment, or a control treatment. We find no effect of either paper on political knowledge, stated opinions, or turnout in post-election survey and voter data. However, receiving either paper led to more support for the Democratic candidate, suggesting that media slant mattered less in this case than media exposure. Some evidence from voting records also suggests that receiving either paper led to increased 2006 voter turnout.
External Link(s)
Registration Citation
Citation
Bergan, Daniel and Dean Karlan. 2016. "Does the Media Matter? A Field Experiment Measuring the Effect of Newspapers on Voting Behavior and Political Opinions." AEA RCT Registry. July 26. https://doi.org/10.1257/rct.1128-1.0.
Former Citation
Bergan, Daniel, Dean Karlan and Dean Karlan. 2016. "Does the Media Matter? A Field Experiment Measuring the Effect of Newspapers on Voting Behavior and Political Opinions." AEA RCT Registry. July 26. https://www.socialscienceregistry.org/trials/1128/history/9612.
Experimental Details
Interventions
Intervention(s)
Households in Prince William County in Virginia, who reported not receiving a newspaper, were randomly assigned to a free ten-week subscription to the conservative Washington Times or the more liberal Washington Post vis-à-vis a control group that did not receive either. Endline survey measured political knowledge, self-reported voter turnout in the November 2005 gubernatorial election and voter turnout data for the November 2005 and 2006 elections from state administrative records.
Intervention Start Date
2005-09-01
Intervention End Date
2005-11-15
Primary Outcomes
Primary Outcomes (end points)
Voter turnout
Knowledge of political issues
Primary Outcomes (explanation)
Voter turnout= self-reported and state administrative records.

Knowledge of political issues = three separate indices were created: Fact Accuracy Index, Specific Policy Index, and the Broad Policy Index. (a) The Fact Accuracy Index is based on responses to three factual questions (identified number dead in Iraq in a closed-ended question, identified “Scooter” Libby from a list of four individuals as Dick Cheney’s chief of staff who recently resigned, identified Harriett Miers from a list of four individuals as a recent female US Supreme Court nominee).
(b) The Specific Issue Index is based on five questions on political issues (three questions about Iraq and the war, a question on the Plame leak, a question about the Alito confirmation).
(c) The Broad Policy Index is based on four questions about attitudes toward the political parties, President Bush, and ideological self-placement on a 7 point scale.
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
Individuals in Prince William County were sampled over the phone from two lists: a list of registered voters and a consumer database list. Respondents who reported receiving no newspaper were chosen for the experimental sample. Individuals were then randomly assigned to one of three conditions: a subscription to the Washington Times, Washington Post or a control group that received neither. The intervention lasted for ten weeks.

The baseline survey checked whether respondents subscribed to a newspaper or not. The endline survey checked the sample respondents’ political knowledge and whether they had voted in the 2005 gubernatorial election. They were not told of any link between the free subscriptions and the initial phone surveys.
Experimental Design Details
Randomization Method
randomization done in office by a computer, using Stata
Randomization Unit
Individuals
Was the treatment clustered?
No
Experiment Characteristics
Sample size: planned number of clusters
3,347 Individuals
Sample size: planned number of observations
3,347 Individuals
Sample size (or number of clusters) by treatment arms
Control:
Washington Times (treatment):
Washington Post (treatment):
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials

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IRB
INSTITUTIONAL REVIEW BOARDS (IRBs)
IRB Name
IRB Approval Date
IRB Approval Number
Post-Trial
Post Trial Information
Study Withdrawal
Intervention
Is the intervention completed?
Yes
Intervention Completion Date
November 15, 2005, 12:00 AM +00:00
Is data collection complete?
Yes
Data Collection Completion Date
December 31, 2006, 12:00 AM +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
1,081 individuals (not clustered)
Was attrition correlated with treatment status?
No
Final Sample Size: Total Number of Observations
1,081 individuals
Final Sample Size (or Number of Clusters) by Treatment Arms
Control: Washington Times: Washington Post:
Data Publication
Data Publication
Is public data available?
Yes
Program Files
Program Files
Reports and Papers
Preliminary Reports
Relevant Papers
Abstract
DOES THE MEDIA MATTER? A FIELD EXPERIMENT MEASURING THE EFFECT OF NEWSPAPERS ON VOTING BEHAVIOR AND POLITICAL OPINIONS

We conducted a field experiment to measure the effect of exposure to newspapers on political behavior and opinion. Before the 2005 Virginia gubernatorial election, we randomly assigned individuals to a Washington Post free subscription treatment, a Washington Times free subscription treatment, or a control treatment. We find no effect of either paper on political knowledge, stated opinions, or turnout in post-election survey and voter data. However, receiving either paper led to more support for the Democratic candidate, suggesting that media slant mattered less in this case than media exposure. Some evidence from voting records also suggests that receiving either paper led to increased 2006 voter turnout.
Citation
Gerber, Alan S., Dean Karlan, and Daniel Bergan. 2009. "Does the Media Matter? A Field Experiment Measuring the Effect of Newspapers on Voting Behavior and Political Opinions." American Economic Journal: Applied Economics 1(2): 35-52.