NEW UPDATE: Completed trials may now upload and register supplementary documents (e.g. null results reports, populated pre-analysis plans, or post-trial results reports) in the Post Trial section under Reports, Papers, & Other Materials.
Effects of tax schedules on perceived income distributions
Last registered on March 12, 2019


Trial Information
General Information
Effects of tax schedules on perceived income distributions
Initial registration date
March 05, 2019
Last updated
March 12, 2019 7:09 AM EDT
Primary Investigator
University of Warwick
Other Primary Investigator(s)
Additional Trial Information
In development
Start date
End date
Secondary IDs
Citizens do not usually have accurate information on population income distributions and their income rank position, and hence create beliefs of those measures based on partial information. The literature of income comparison has found that reference income of co-workers and personal network have a significant impact on those perceptions, but other influential factors remain unknown. Are tax schedules used by taxpayers as signals on the actual income distribution? Under certain assumptions on how the government designs tax system, changes on the tax burden applied to different levels of income may be used as signals of the actual income densities. Using an online experiment where workers face different tax systems, I aim to identify the potential impact of the structure of tax scales on perceived income distributions and self income rank.
External Link(s)
Registration Citation
Diez-Alonso, Daniel. 2019. "Effects of tax schedules on perceived income distributions." AEA RCT Registry. March 12. https://doi.org/10.1257/rct.3978-1.0.
Former Citation
Diez-Alonso, Daniel. 2019. "Effects of tax schedules on perceived income distributions." AEA RCT Registry. March 12. http://www.socialscienceregistry.org/trials/3978/history/43177.
Sponsors & Partners

There are documents in this trial unavailable to the public. Use the button below to request access to this information.

Request Information
Experimental Details
Workers perform some tasks to earn income, which is then subject to an income tax system. Questions on perceived distributions and self income rank follow.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
Perceived Income Distribution; Perceived Income Rank
Primary Outcomes (explanation)
Perceived distributions are elicited by incentivised questions on frequency for different ranges of income. Perceived Income Rank is asked directly.
Secondary Outcomes
Secondary Outcomes (end points)
Perceptions on fairness of tax burden.
Secondary Outcomes (explanation)
Usual type of questions as in regular surveys: "Do you think high earners pay too much / about right / too little taxes?"
Experimental Design
Experimental Design
Workers face different tax systems where the tax burden randomly varies across specific ranges of income. The control group faces the same income schedule in both rounds.
Experimental Design Details
Comparison occurs between workers (within round) and within workers (between rounds). Workers face different tax schemes according to (random) treatment at each round, which differ on the structure of the tax brackets (hence resulting on different tax burden on different levels of income). The changes take place in isolated changes, either by changing the level of a given tax band or by adding/subtracting an additional tax band. Two of the treatments increase tax burden at higher incomes (wrt lower incomes) and the other two treatments reduce tax burden at higher incomes (wrt lower incomes). In addition, those changes on the tax schedule also result on a different marginal tax band assigned to each worker. By randomizing the earned income fraction that forms the taxable income of each round, I can test whether identification with a "tax group" also has an effect on perceived income rank. In this case, individuals with same income level in both rounds act as control for individuals with changing income.
Randomization Method
Random treatment assigned by the program.
Randomization Unit
Individual and round. Randomization affects to both income used in each round (as a random fraction of income earned performing tasks) and to the tax system faced in each round, by each player.
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
600 people
Sample size: planned number of observations
1200 perceived distributions and income rank (2 rounds per worker)
Sample size (or number of clusters) by treatment arms
There are 4 treatment groups of 100 workers (facing 4 different treatments) and two control groups of 100 workers.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB Name
Humanities & Social Sciences Research Ethics Committee (HSSREC) - University of Warwick
IRB Approval Date
IRB Approval Number
Post Trial Information
Study Withdrawal
Is the intervention completed?
Is data collection complete?
Data Publication
Data Publication
Is public data available?
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)