Does Political Corruption Cumulate in Its Effects?

Last registered on September 09, 2021


Trial Information

General Information

Does Political Corruption Cumulate in Its Effects?
Initial registration date
September 08, 2021

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
September 09, 2021, 7:30 PM EDT

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



Primary Investigator

Stanford Graduate School of Business

Other Primary Investigator(s)

PI Affiliation
PI Affiliation

Additional Trial Information

In development
Start date
End date
Secondary IDs
Prior work
This trial is based on or builds upon one or more prior RCTs.
The last decade has witnessed a large increase in the perception of corruption in Latin America, and at the same time a decrease in preferences for democracy and trust. In a previous RCT, "Rebuilding Trust, Social Cohesion and Democratic Values", ( we randomly assigned videos documenting politicians from different parties taking bribes in Mexico, among other treatments, to see whether the relationship between corruption and lack of trust in democracy is causal and how democratic values can be restored.

One open question, however, is whether political corruption cumulates in its effects. In other words, whether, exposure to additional evidence of corruption has an effect relative to just one. In this RCT, we exploit new video evidence that came to light during our previous RCT to examine this question.
External Link(s)

Registration Citation

Jha, Saumitra, Eduardo Rivera and Enrique Seira Bejarano. 2021. "Does Political Corruption Cumulate in Its Effects?." AEA RCT Registry. September 09.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
We will ask the following survey questions after the video.
1. Preference for democracy using questions adapted from Latinobarometer, including:
“In general, would you say you are very satisfied, somewhat satisfied, a little satisfied or not satisfied with the democracy in Mexico?”,
“On a scale from 1-10 we ask you to evaluate how democratic is Mexico”, etc.

2. Perceptions about the prevalence of corruption, including:
“How much progress do you think has been made in reducing corruption within State institutions in these past 2 years?”,
“Which party do you think is the most corrupt”, etc.

3. Survey measures of voting, including:
“If presidential elections were to be held this Sunday, which party would you vote for?”

We will ask them for which party they voted in the past election, before the video, to evaluate the effect of the first videos on real voting. We will also ask a question about trust in specific institutions: “Please state, for each one of the groups, institutions or people mentioned in the following list, how much trust do you have in them”
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We will randomly assign 1/2 of a sample of 1750 individuals news footage of corruption.
Experimental Design Details
Randomization Method
Randomization done in an office by a computer.
Randomization Unit
Randomization at the individual level.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
1750 individually randomized adults.
Sample size: planned number of observations
1750 subjects: adults with a valid voting ID
Sample size (or number of clusters) by treatment arms
We will have 875 per treatment arm (though fewer in specific sub-treatment cells, see below).
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Some approximate power calculations (that don’t include control variables) suggest that the power to detect changes in one of the main democracy variables may be fine overall but limited for examining differential effects across subtreatments. The democracy outcome variable we tested is a dummy variable with a mean of 0.27. In the first round of the experiment we found that the corruption video shown decreases preference for democracy as measured by this variable by 0.07. Based on that, we calculate that, to detect an effect of such size with 80% power and 95% confidence, we would need 600 observations per arm (that is 600 assigned to the 2nd video, and 600 assigned to no-2nd video). If instead we had say 200 observations per arm, the power we would have will be close to 33%. And if we had 400 observations per arm, power would be close to 61%. Given this, we seem to be well powered to compare the “overall” effect of the second video, across all previous treatment conditions. But our power to test for instance whether the effect of this new corruption video for those that got a first corruption video in the first round, is limited, and around 33%.

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number
IRB Name
Stanford IRB
IRB Approval Date
IRB Approval Number


Post Trial Information

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials