Social insurance contribution: supporting correct payments

Last registered on August 14, 2024
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Pre-Trial

Trial Information

General Information

Title
Social insurance contribution: supporting correct payments
RCT ID
AEARCTR-0010133
Initial registration date
November 03, 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 04, 2022, 1:30 PM EDT

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

Last updated
August 14, 2024, 11:00 AM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Country
Slovakia
Region

Primary Investigator

Name
Zuzana Brokesova
Affiliation
University of Economics in Bratislava
Contact Primary Investigator

Other Primary Investigator(s)

PI Name
Jana Peliova
PI Affiliation
University of Economics in Bratislava
Contact Investigator
PI Name
Richard Priesol
PI Affiliation
Ministry of Finance of the Slovak Republic
Contact Investigator
PI Name
Anna Makarova
PI Affiliation
Ministry of Investment, Regional Development and Informatics of the Slovak Republic
Contact Investigator

Additional Trial Information

Status
Completed
Start date
2022-10-23
End date
2024-01-31
Keywords
Behavior, Governance, Welfare
Additional Keywords
JEL code(s)
C93 D02 H55
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This document describes a randomized controlled trial (RCT) in Slovak Republic to identify intervention that help self-employed person to pay social insurance contribution's in correct amount. Social insurance in Slovakia is a complex system. The sum of contributions depends on several factors including income, etc. These factors change regularly, so the contribution change regularly as well. However, not all self-employed persons are able to follow these changes and as a result they pay wrong contribution amount or do not pay contributions. Prior research shows that simplification of the communicated information, moral appeal or deterrence could help increase the payment moral. Our study aims to test the effect of these interventions on payment moral of self-employed person in the Slovak Republic. We use the letter experiment to employ interventions known in the literature.
External Link(s)

Registration Citation

Citation
Brokesova, Zuzana et al. 2024. "Social insurance contribution: supporting correct payments." AEA RCT Registry. August 14. https://doi.org/10.1257/rct.10133-2.0
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Experimental Details

Interventions

Intervention(s)
Intervention is based on the adjustments of the content of letters announcing the social insurance contribution details that Social Insurance Agency in Slovakia is sending to the self-employed individuals.
Intervention Start Date
2022-10-23
Intervention End Date
2023-07-31

Primary Outcomes

Primary Outcomes (end points)
number of self-employed individuals who pay within each treatment correct amount of contribution, number of self-employed individuals who pay within each treatment non-zero, number of self-employed individuals who pay within each treatment incorrect amount of contribution
Primary Outcomes (explanation)
NA

Secondary Outcomes

Secondary Outcomes (end points)
gender effect, social insurance experience, occupational effect, sector of operation effect, education effect and geographical distribution
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Described experiment represents letter experiment. We adjust the content of letters defining the social insurance premium payment details that Social Insurance Agency in Slovakia is obligate to send to the self-employed individuals. In usual and law defined period, the letters are send by usual way in printed and electronic version (by Slovak Post Office and to electronic mailbox). Experimental subjects are self-employed individuals who (1) have newly incurred the obligation to pay contributions on social insurance, (2) have repeatedly incurred the obligation to contributions on pay social insurance and (3) whose amount on contributions on social insurance change. Our design include baseline and four treatments.


Experimental Design Details
Described experiment represents letter experiment. We adjust he content of letters defining the social insurance contributions details that Social Insurance Agency in Slovakia is based on the law obligate to send to the self-employed individuals. The letter defines the social insurance contributions details. In usual and law defined period, the letters are send by usual way in printed and electronic version (by Slovak Post Office and to electronic mailbox). In our design only printed letters distributed by Slovak Post Office was used. Experimental subjects are self-employed individuals who (1) have newly incurred the obligation to pay contributions on social insurance, (2) have repeatedly incurred the obligation to contributions on pay social insurance and (3) whose amount on contributions on social insurance change. The experiment was run in two waves. In the first wave, we included self-employed who had an extended deadline for filing their 2021 tax return. This group was contacted in October 2022. In the second wave, we then included self-employed who filed their 2022 tax return by the regular deadline. This group was contacted in July 2023. In case of self-employed persons who have become liable to pay contributions (a and b), control group (T0) and all four treatments (T1-T4) were tested. In case of self-employed persons whose contribution has changed (c), only control group (T0), simplification treatment (T1) and deterrence (T2) was tested.

Treatment within above-mentioned groups of experimental subjects are as follows:
(1) self-employed individuals who have newly incurred the obligation to pay premiums on social insurance
a/ Intervention: simplification
b/ Intervention: deterrence
c/ Intervention: simplification + orthogonal treatment (leaflet)
d/ Intervention: deterrence + orthogonal treatment (leaflet)
e/ control

(2) self-employed individuals who have repeatedly incurred the obligation to premiums on pay social insurance
a/ Intervention: simplification
b/ Intervention: deterrence
c/ Intervention: simplification + orthogonal treatment (leaflet)
d/ Intervention: deterrence + orthogonal treatment (leaflet)
e/ control

(3) self-employed individuals whose amount on premiums on social insurance change based on income change
a/ Intervention: simplification
b/ Intervention: deterrence
e/ control


Randomization Method
Randomization is done on individual level based on the data form the Social Insurance Agency (sex, age, place of residence, size of the city, type of trade and assessment base). Randomization will be done in Stata. We control for assignment of same treatment for members of same household (if it is the case).
Randomization Unit
Individual self-employed person
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
136 025 self-employed person
Sample size: planned number of observations
136 025 self-employed person
Sample size (or number of clusters) by treatment arms
From this sample, there are 8 826 in the first wave and 19 459 in the second wave self-employed persons who have become liable to pay contributions. In the case of self-employed individuals whose contribution changed, sub sample consists of 28 591 self-employed individuals in the first wave and 79 149 self-employed individuals in the second wave or randomized control trial.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Based on the power analysis calculations, our samples for treatments and control enable us to identify medium effect size of intervention in comparison to control group with more than 99% power for each treatment in each self-employed person group. We use G*Power for power calculations.
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
Ethics Commitee of the University of Economics in Bratislava
IRB Approval Date
2022-10-13
IRB Approval Number
EKEUBA-IV1-2/2022
Analysis Plan

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
Yes
Intervention Completion Date
July 31, 2023, 12:00 +00:00
Data Collection Complete
Yes
Data Collection Completion Date
October 31, 2023, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
136 025 self-employed person
Was attrition correlated with treatment status?
No
Final Sample Size: Total Number of Observations
136 025 self-employed person
Final Sample Size (or Number of Clusters) by Treatment Arms
3 groups of self-employed person
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
No
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials