Social security premiums: correct and on time payment

Last registered on April 11, 2023

Pre-Trial

Trial Information

General Information

Title
Social security premiums: correct and on time payment
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
April 11, 2023, 8:12 AM EDT

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

Locations

Region

Primary Investigator

Affiliation
University of Economics in Bratislava

Other Primary Investigator(s)

PI Affiliation
University of Economics in Bratislava
PI Affiliation
Ministry of Finance of the Slovak Republic
PI Affiliation
Ministry of Investment, Regional Development and Informatics of the Slovak Republic

Additional Trial Information

Status
Completed
Start date
2022-10-23
End date
2023-02-17
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 premium on time and in correct amount. Social insurance in Slovakia is a complex system. The sum of premium depends on several factors including living wage, level of income, etc. These factors change regularly, so the premium change regularly as well. However, not all self-employed persons are able to follow these changes and as a result they pay wrong premium amount or do not pay premium on time. 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. 2023. "Social security premiums: correct and on time payment." AEA RCT Registry. April 11. https://doi.org/10.1257/rct.10133-1.1
Sponsors & Partners

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

Request Information
Experimental Details

Interventions

Intervention(s)
Intervention is based on the adjustments of the content of letters announcing the social insurance premium payment details that Social Insurance Agency in Slovakia is sending to the self-employed individuals.
Intervention Start Date
2022-10-23
Intervention End Date
2023-01-31

Primary Outcomes

Primary Outcomes (end points)
number of people who pay within each treatment: a) on time, b) on time and in correct amount
Primary Outcomes (explanation)
NA

Secondary Outcomes

Secondary Outcomes (end points)
gender effect, occupational 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 premiums on social insurance, (2) have repeatedly incurred the obligation to premiums on pay social insurance and (3) whose amount on premiums on social insurance change. Our design include baseline, two treatments and one orthogonal treatment (leaflet). Each treatment have a individual control group.


Experimental Design Details
Described experiment represents letter experiment. We adjust he content of letters defining the social insurance premium payment 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 premium payment 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). Experimental subjects are self-employed individuals who (1) have newly incurred the obligation to pay premiums on social insurance, (2) have repeatedly incurred the obligation to premiums on pay social insurance and (3) whose amount on premiums on social insurance change. Our design include baseline (letters sent on July 2022), two treatments, one orthogonal treatment (leaflet focusing on moral appeal) and a control (letters send on January 2023). Each treatment have a individual control group based on the data following original letter that will be send in January 2023.

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 (level of income, gender, age, geographical residence, city size, type of occupation). 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
37 570 self-employed person
Sample size: planned number of observations
37 570 self-employed person
Sample size (or number of clusters) by treatment arms
(1) self-employed individuals who have newly incurred the obligation to pay premiums on social insurance (5 482 subjects equally distributed among treatments)
(2) self-employed individuals who have repeatedly incurred the obligation to premiums on pay social insurance (3 345 subjects subjects equally distributed among treatments)
(3) self-employed individuals whose amount on premiums on social insurance change based on income change (28 743 subjects subjects equally distributed among treatments)


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.
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

Post-Trial

Post Trial Information

Study Withdrawal

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

Request Information

Intervention

Is the intervention completed?
Yes
Intervention Completion Date
January 31, 2023, 12:00 +00:00
Data Collection Complete
Yes
Data Collection Completion Date
January 31, 2023, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
37 570 self-employed person
Was attrition correlated with treatment status?
No
Final Sample Size: Total Number of Observations
37 570 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