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Interoperable Payment Systems, Payment Flows and Open Banking Complementarities: Evidence from Brazil

Last registered on April 10, 2025
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Pre-Trial

Trial Information

General Information

Title
Interoperable Payment Systems, Payment Flows and Open Banking Complementarities: Evidence from Brazil
RCT ID
AEARCTR-0015773
Initial registration date
April 09, 2025

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
April 10, 2025, 7:39 AM EDT

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

Locations

Country
Brazil
Region

Primary Investigator

Name
Giorgia Barboni
Affiliation
University of Warwick, Warwick Business School
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Other Primary Investigator(s)

PI Name
Lucas Argentieri Mariani
PI Affiliation
Bocconi University
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PI Name
Bernardo Guerra Ricca
PI Affiliation
INSPER
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PI Name
Jose Renato Ornelas
PI Affiliation
Central Bank of Brazil
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Additional Trial Information

Status
On going
Start date
2025-04-09
End date
2025-06-30
Keywords
Finance & Microfinance, Firms & Productivity
Additional Keywords
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
We study the adoption of Open Finance policies in Brazil and their potential to promote financial inclusion among micro and small firms. Despite widespread use of Pix—an instant payment system launched by the Central Bank of Brazil—only a minority of firms currently participate in Open Finance, which enables data sharing across financial institutions. Our project focuses on firms located in the Metropolitan Region of Greater Vitória. We implement a randomized control trial to assess whether providing information and incentives can increase Open Finance adoption among eligible firms, especially those already using Pix. Treated firms receive a short educational video, follow-up nudges via WhatsApp, and access to a support team to assist with data-sharing enrollment. Outcomes are measured via a follow-up survey and administrative data from the Central Bank of Brazil. The study evaluates whether greater awareness and support around Open Finance can boost adoption and lead to improved access to credit and other financial services.
External Link(s)

Registration Citation

Citation
Argentieri Mariani, Lucas et al. 2025. "Interoperable Payment Systems, Payment Flows and Open Banking Complementarities: Evidence from Brazil." AEA RCT Registry. April 10. https://doi.org/10.1257/rct.15773-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Intervention (Hidden)
Intervention Start Date
2025-04-09
Intervention End Date
2025-06-30

Primary Outcomes

Primary Outcomes (end points)
The study aims to assess the effects of an informational intervention on Open Finance adoption among eligible micro-enterprises. Primary outcomes include:
• Whether the firm opts into Open Finance data-sharing via their financial institution;
• Attitudes and understanding of Open Finance (measured through follow-up survey items);
• Use of new financial products or services following the intervention.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary outcomes include:
• Proxies for financial planning;
• Perceived access to credit;
• Changes in banking behavior (e.g., number of accounts used, institutions compared).
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We aim to recruit 1,170 firms located in the municipalities of Vitória, Vila Velha, Serra, and Cariacica, in the state of Espírito Santo, Brazil. These firms are micro or small businesses that already use Pix and have accounts in at least two different financial institutions.
Firms are assigned to 56 geographic clusters, and treatment is allocated at the cluster level to avoid spillovers. Clustering is based on geographic proximity to ensure clear separation between treatment and control groups.
Firms in the treatment group are shown a short video explaining the benefits of Open Finance and are offered follow-up WhatsApp nudges and access to a support team that can help them enroll in Open Finance. Firms in the control group do not receive this information. All firms are surveyed again in a follow-up interview approximately two weeks after the initial baseline.
Participants are compensated in-kind for completing the baseline and the follow-up survey.

Experimental Design Details
Randomization Method
Done in office via Stata command
Randomization Unit
Each cluster corresponds to a group of firms based on proximity via the K-Means method (the closest real-world equivalent is a neighborhood)
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
56 geographical clusters
Sample size: planned number of observations
We plan to recruit 1,170 firms to participate in the baseline survey. Based on updated power calculations, and accounting for the exclusion of firms with multiple branches, we expect approximately 986 valid observations for analysis. These firms are distributed across 56 clusters, with an average of 17 firms per cluster. Power simulations using various intra-cluster correlation (ICC) values—ranging from 0.004 to 0.08—indicate that, even under more conservative assumptions, the minimum detectable effect (MDE) remains below 0.14 standard deviations. These simulations provide confidence that our sample is adequately powered to detect meaningful impacts from the intervention.
Sample size (or number of clusters) by treatment arms
28 clusters per treatment arm
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
IPA Global Research & Data Science (GRDS)
IRB Approval Date
2025-04-04
IRB Approval Number
16856
Analysis Plan

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials