Perceived sustainable minimum wages – a test of randomization and question scales across countries

Last registered on November 17, 2022


Trial Information

General Information

Perceived sustainable minimum wages – a test of randomization and question scales across countries
Initial registration date
November 11, 2022

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
November 17, 2022, 3:30 PM EST

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


Primary Investigator

Austrian Central Bank

Other Primary Investigator(s)

PI Affiliation
Austrian Central Bank

Additional Trial Information

Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
We implement a survey experiment in the 2022 wave of the OeNB Euro Survey. The OeNB Euro Survey is a repeated cross-sectional survey conducted annually in ten different countries. The aim of the survey experiment is threefold. First, we test the feasibility of different randomization approaches across countries and whether falsification or errors in implementation regarding randomization might be a concern. Second, we examine data falsification in terms of individual responses. If there is evidence of data falsification, these effects how interviewers or survey institutes behave, would influence and/or blur treatment effects in respondents’ behavior. Third, we test a standard assumption in survey research regarding scale transformation. It is common in surveys when asking respondents to report wages to give them the choice which reporting unit to use, i.e. wage per hour, month or year. If these questions are used in research projects, numbers are then often set to the same scale. In our treatment, we vary on which scale respondents are supposed to report a specific wage. This experiment allows us to analyze if the assumption of, e.g., linear transformation based on full-time working hours, is valid.
External Link(s)

Registration Citation

Beckmann, Elisabeth and Melanie Koch. 2022. "Perceived sustainable minimum wages – a test of randomization and question scales across countries." AEA RCT Registry. November 17.
Experimental Details


See pre-analysis plan
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
min_wage_hr: Perceived minimum amount people living in the same town/village should approximately earn per hour after taxes
min_wage_mth: Perceived minimum amount people living in the same town/village should approximately earn per month after taxes
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
min_wage_yr: Perceived minimum amount people living in the same town/village should approximately earn per year after taxes
Secondary Outcomes (explanation)
min_wage_yr is only asked in three of ten countries (Bulgaria, Romania and Serbia) if respondents answer 'don't know' on min_wage_hr.

Experimental Design

Experimental Design
We randomize at which scale respondents of the survey have to answer what, in their personal opinion, is the minimum amount people living in their town/village should approximately earn. One treatment group is asked about the amount per hour, the other group about the amount per month. The question is asked after several questions about personal finances are answered, right before respondents answer further questions on socio-demographic information. Survey contractors in each country were told to randomize over respondents but to stratify over interviewers, so that we can control for interviewer effects.
Experimental Design Details
Randomization Method
Randomization methods deliberately differ across countries:
Randomization (alternating order of treatments) for all CAPIs is computerized but sometimes require data entry from the interviewer
Randomization (alternating order of treatments) for all PAPIs is done by hand by the survey contractors
The different approaches are outlined in the pre-analysis plan.
Randomization Unit
Randomization by survey respondent, stratified by interviewer
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
The treatment is not clustered but it is conducted in ten different countries and we will mostly look at these countries separately. In each country, 1,000 interviews are conducted, i.e., 500 interviews per treatment group.
Sample size: planned number of observations
In total, around 10,000: at least 1,000 respondents in each country
Sample size (or number of clusters) by treatment arms
In total, around 5,000: at least 500 respondents per treatment in each country
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
See pre-analysis plan

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number
Analysis Plan

Analysis Plan Documents

Perceived sustainable minimum wages_PAP

MD5: 74d1e320749dcc9afb609aa5acc351b5

SHA1: a5bdb27f999f8ac38c6fb2c9ebc5ea7af83ef0c7

Uploaded At: November 11, 2022


Post Trial Information

Study Withdrawal

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

Request Information


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