Inflation Beliefs and the Indexation of Household Debt

Last registered on August 27, 2026
View Trial History

Pre-Trial

Trial Information

General Information

Title
Inflation Beliefs and the Indexation of Household Debt
RCT ID
AEARCTR-0019465
Initial registration date
August 20, 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
August 27, 2026, 11:48 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
Otavio Braga
Affiliation
Duke University
Contact Primary Investigator

Other Primary Investigator(s)

PI Name
Caio Castro
PI Affiliation
FGV EESP - Sao Paulo School of Economics
PI Name
Joao Pugliese
PI Affiliation
Stanford University
PI Name
Lucas Iten Teixeira
PI Affiliation
Central Bank of Brazil

Additional Trial Information

Status
In development
Start date
2026-06-30
End date
2027-04-30
Keywords
Finance & Microfinance, Other
Additional Keywords
Inflation beliefs; household debt; indexation; mortgage design
JEL code(s)
D14, E31, C83, G51, D84
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Price-level-adjusted (PLA) debt indexes household liabilities to consumer prices. Relative to conventional fixed-nominal contracts, it offers lower initial installments but generates a rising and uncertain path of future payments. Planning under such a contract requires households both to form inflation expectations over long horizons and to translate those expectations into their own future nominal installments. We conduct a survey experiment with PLA borrowers in Brazil with two cross-randomized treatment arms that separately target (i) inflation beliefs, by providing information on realized inflation, and (ii) the translation of beliefs into projected installments, by demonstrating how inflation compounds into the future payment path. The design lets us measure both perceptions on borrowers' own contracts and generate exogenous variation in each, which we use to estimate their effects on projected installments, intended saving, and stated preferences over indexed versus fixed-installment contracts.
External Link(s)

Registration Citation

Citation
Braga, Otavio et al. 2026. "Inflation Beliefs and the Indexation of Household Debt." AEA RCT Registry. August 27. https://doi.org/10.1257/rct.19465-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
We survey borrowers in Brazil who hold inflation-indexed debt, whose monthly payments rise with inflation over the life of the contract. The survey measures how well these borrowers anticipate the future path of their own payments, how much they expect to save to prepare for it, and how they value the option of switching to a fixed payment instead. Embedded in the survey is a short information intervention: some participants are given information about inflation, and some are shown how inflation accumulates into their future payments over time. By comparing responses across these groups, we study how correcting what borrowers know about inflation—and about how it maps into their own debt—changes their expectations, their saving plans, and their contract preferences.
Intervention Start Date
2026-08-21
Intervention End Date
2026-10-15

Primary Outcomes

Primary Outcomes (end points)
(1) The projected nominal installment over the survey horizon. (2) Willingness to switch to a fixed-installment contract, measured by the maximum installment increase the participant would accept to switch. (3) Intended monthly saving toward future installment increases.
Primary Outcomes (explanation)
Each outcome comes directly from a survey question. The projected installment is the participant's stated guess of their monthly payment five years out. Willingness to switch is the largest percentage increase they say they would accept to move to a fixed installment. Intended saving is the monthly amount they report setting aside for future increases.

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The experiment is a survey-based information intervention administered to price-level-adjusted (PLA) borrowers—participants in Brazilian consórcios who have to repay installments corrected by a price index. The design is a 2×2 factorial that cross-randomizes two treatments at the individual level: a Belief arm (B), which provides information on different moments of the historical distributiion of annualized inflation, and a Projection arm (P), which demonstrates how inflation compounds into the borrower's future nominal installment path. Crossing the two yields four cells: pure control, Belief only, Projection only, and both.
Experimental Design Details
Not available
Randomization Method
Randomization of the main intervention is done through Qualtrics' survey flow "Randomizer" block with the "Evenly Present Elements" enabled.
Randomization Unit
Individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
1000 borrowers
Sample size: planned number of observations
1000 borrowers
Sample size (or number of clusters) by treatment arms
500 borrowers for both (B) and (P) treatment arms
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
FGV CEPH (Fundação Getúlio Vargas)
IRB Approval Date
2026-03-04
IRB Approval Number
P.645.2025
Analysis Plan