Municipal Responsiveness to Email Inquiries in Germany: An Email Correspondence Experiment on Requests about School Support Aides for Children with Special Educational Needs versus Parking Permits and Name-Based Differences in Responses.

Last registered on February 04, 2026

Pre-Trial

Trial Information

General Information

Title
Municipal Responsiveness to Email Inquiries in Germany: An Email Correspondence Experiment on Requests about School Support Aides for Children with Special Educational Needs versus Parking Permits and Name-Based Differences in Responses.
RCT ID
AEARCTR-0017714
Initial registration date
January 30, 2026

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
February 04, 2026, 10:01 AM EST

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

Locations

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Primary Investigator

Affiliation
Siegen University

Other Primary Investigator(s)

PI Affiliation
University of Siegen

Additional Trial Information

Status
In development
Start date
2026-03-01
End date
2026-04-30
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This study investigates how German municipalities respond to citizen email inquiries and whether responses differ by request type and sender characteristics. The study uses a randomized email correspondence design in which municipalities receive standardized messages requesting information either on applying for a school support aide (“Integrationshelfer”) for a child with formally assessed special educational needs or on applying for a parking permit. Sender names are randomly varied to signal a German-sounding versus Arabic-sounding name, and sender gender is also varied. Outcomes include whether municipalities respond, the helpfulness of responses (measured on a five-point scale), and whether replies include follow-up questions or requests for additional documents. For the school support aide inquiry, the study additionally records whether replies use relevant technical terminology related to special educational needs and whether they suggest telephone contact or a call-back. Comparing outcomes across request types and sender signals allows the study to assess whether access to administrative information and service quality vary systematically with the perceived background or gender of the requester and whether such patterns differ between education-related support and administrative permit requests.
External Link(s)

Registration Citation

Citation
Köhler, Ekkehard and Julia Niggemeyer. 2026. "Municipal Responsiveness to Email Inquiries in Germany: An Email Correspondence Experiment on Requests about School Support Aides for Children with Special Educational Needs versus Parking Permits and Name-Based Differences in Responses.." AEA RCT Registry. February 04. https://doi.org/10.1257/rct.17714-1.0
Experimental Details

Interventions

Intervention(s)
Intervention Start Date
2026-03-01
Intervention End Date
2026-03-31

Primary Outcomes

Primary Outcomes (end points)
Response indicator (whether the municipality replies to the email).
Helpfulness / information quality of the reply (five-point helpfulness rating).
Follow-up requirements (whether the reply asks follow-up questions and/or requests additional documents).
For the school support aide inquiry: use of relevant technical terminology related to special educational needs and whether the municipality suggests telephone contact / a call-back.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
This study uses a randomized email correspondence design to examine municipal responsiveness and information provision. The unit of observation is the municipality. Each municipality receives one standardized email inquiry from a hypothetical citizen. Emails are randomly assigned in a factorial design that varies (i) the topic of the request—information on how to apply for a school support aide (“Integrationshelfer”) for a child with formally assessed special educational needs versus information on how to apply for a parking permit—and (ii) sender characteristics. Sender names are randomly varied to signal a German-sounding versus Turkish-sounding name, and sender gender is also varied (male vs female name). Municipal responses are collected from email replies and coded for responsiveness and content characteristics. Comparisons across randomized conditions are used to assess whether response rates and the content of replies differ by request type and by perceived sender background and gender.
Experimental Design Details
Not available
Randomization Method
Random assignment was conducted using a computer-generated randomization procedure. Each municipality was randomly assigned to one of the experimental conditions in a 2×2×2 factorial design (request topic: school support aide vs parking permit; name signal: German-sounding vs Turkish-sounding; sender gender: male vs female). Randomization was implemented prior to sending the emails.
Randomization Unit
The unit of randomization is the municipality (one email per municipality).
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
Number of clusters (unit = municipality): 1,800 municipalities (one email per municipality).
Sample size: planned number of observations
1,800 emails sent to municipalities (one observation per email / municipality contact).
Sample size (or number of clusters) by treatment arms
Planned allocation across 8 conditions (2×2×2 factorial design):
School support aide inquiry:
German-sounding name × female (Vanessa Fischer): 226 municipalities
German-sounding name × male (Timo Schulz): 226 municipalities
Turkish-sounding name × male (Hasim Aksoy): 226 municipalities
Turkish-sounding name × female (Zümra Cetin): 220 municipalities
Parking permit inquiry
German-sounding name × female (Vanessa Fischer): 227 municipalities
German-sounding name × male (Timo Schulz): 226 municipalities
Turkish-sounding name × male (Hasim Aksoy): 224 municipalities
Turkish-sounding name × female (Zümra Cetin): 225 municipalities
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
Rat für Ethik in der Forschung, Universität Siegen
IRB Approval Date
2023-01-15
IRB Approval Number
ER_20_2023