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Memories of the Stock Market

Last registered on April 06, 2026
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Pre-Trial

Trial Information

General Information

Title
Memories of the Stock Market
RCT ID
AEARCTR-0018258
Initial registration date
March 31, 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
April 06, 2026, 7:56 AM EDT

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

Locations

Country
United States of America
Region

Primary Investigator

Name
ivo welch
Affiliation
ucla
Contact Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Status
In development
Start date
2026-03-31
End date
2026-05-31
Keywords
Finance & Microfinance
Additional Keywords
JEL code(s)
Secondary IDs
Prior work
This trial is based on or builds upon one or more prior RCTs.
Abstract


This study replicates and extends an earlier survey (AEARCTR-0018154) that documented how recalled past S&P 500 returns drive expectations of future returns. The original study found that (a) recalled returns predicted expected returns (standardized beta = 0.36--0.41), (b) showing actual returns produced modest upward revisions (+1.9% at 12m, +1.2% at 5y), (c) self-reported surprise amplified the revision, (d) the BGS norm-surprise mechanism was rejected, (e) order and nudge manipulations had no effect, and (f) market recall dominated personal portfolio returns 2.5:1.

The new survey (v6) introduces two major innovations. First, a deception treatment randomly shows some respondents an artificially low 2025 return (5%) instead of the actual return (18%), followed by a debrief that reveals the truth. This separates information anchoring from genuine memory-error correction. Second, a post-reveal "typical annual return" question tests whether the subjective norm itself shifts in response to revealed information. Additional new measures include self-reported optimism and risk aversion.

The pre-registration below codifies the original findings as directional replication hypotheses (R1--R12), formulates new hypotheses for the v6 features (N1--N7), and specifies estimation methods.

(The earlier data will be used also, but the paper plans to report separately if anything changes between earlier data and the to-be-performed data.)

External Link(s)

Registration Citation

Citation
welch, ivo. 2026. "Memories of the Stock Market." AEA RCT Registry. April 06. https://doi.org/10.1257/rct.18258-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)

1. Deceptive 2025 Return (between-subjects, 50/50 or similar split):
- Truth condition: Participants see the actual 2025 S&P 500 return of 18% on the information reveal page.
- Deception condition: Participants see a fabricated 2025 return of 5%. The time series chart is truncated to Dec 2024. A debrief page after the post-expectation questions reveals the true 18% return and asks a 4-option reaction question (already_knew / suspected_strong / suspected_weak / deceived).

2. Order Randomization (between-subjects, 50/50):
- Recall-first: Recall sections (B--E) precede pre-information expectations (F).
- Expect-first: Pre-information expectations (F) precede recall sections (B--E).
Same as in the original study.

3. Post-Reveal Typical Return Question:
The same "typical annual return" question (D1) is re-asked after the information reveal, allowing measurement of norm shift.

4. New Demographics:
Self-reported optimism (1--5) and risk aversion (1--5) are added after the political leaning question. Demographics question order is randomized (except the attention check, which is always last).
Intervention (Hidden)
Intervention Start Date
2026-03-31
Intervention End Date
2026-05-31

Primary Outcomes

Primary Outcomes (end points)
rimary Outcomes (end points)

A. Replication Outcomes (same as original study)

Variable Description Type
ExpctPre.1Y (F1) Pre-information 12-month expected return numeric (%)
ExpctPre.5Y (F3) Pre-information 5-year expected annual return numeric (%)
ExpctPost.1Y (H1) Post-information 12-month expected return numeric (%)
ExpctPost.5Y (H3) Post-information 5-year expected annual return numeric (%)
ExpRev.1Y (H1 - F1) Belief revision: 12-month numeric (pp)
ExpRev.5Y (H3 - F3) Belief revision: 5-year numeric (pp)
OthExpctPre.1Y (F2) Perceived consensus 12-month expectation numeric (%)
OthExpctPost.1Y (H2) Post-information perceived consensus numeric (%)
OthExpRev.1Y (H2 - F2) Revision in perceived consensus numeric (pp)
Mkt.Too.High (F4/H4) "Is the market too high?" categorical
Regret (F6/H6) Investment regret (pre and post) ordinal
Recall.1Y (C1) Recalled 2025 S&P 500 return numeric (%)
Recall.5Y (B2) Recalled 2020--2025 annual return numeric (%)
Typical.Y (D1) Perceived typical annual return numeric (%)
OwnPerf.1Y (E1) Own portfolio return in 2025 numeric (%)
MmryErr.1Y (Actual - C1) Memory error numeric (pp)
Surprise (G1) Self-reported surprise at actual returns ordinal (1--3)

B. New Outcomes (v6)

Variable Description Type
Typical.Y.Post (D1 post) Post-reveal typical annual return numeric (%)
NormShift (D1.post - D1.pre) Change in perceived norm numeric (pp)
shown_return_1y Displayed return (5% or 18%) treatment indicator
debrief_reaction Whether deception was detected categorical (4 levels)
optimist Self-reported optimism ordinal (1--5)
risk_averse Self-reported risk aversion ordinal (1--5)
Primary Outcomes (explanation)
The primary outcomes are the same belief revision measures as in the original study (ExpRev.1Y, ExpRev.5Y, OthExpRev.1Y), now augmented by: (1) the deception treatment comparison (revision under 5% vs 18% shown return), (2) the norm shift (Typical.Y.Post - Typical.Y), and (3) deception detection rates.

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (end points)

- Mkt.Too.High switching (F4 != H4)
- Regret revision (H6 - F6)
- Surprise x Revision interaction
- Confidence x Recall interaction
- PCA factor structure (replication of 2-factor solution)
- Source attribution and recall accuracy
- Narrative theme associations
- Optimism and risk aversion as predictors of recall and expectations
- Demographics order effects
Secondary Outcomes (explanation)
These are either replications of secondary findings from the original study or exploratory analyses enabled by new v6 variables.

Experimental Design

Experimental Design
Prolific
Experimental Design Details
Randomization Method
RNG
Randomization Unit
by prolific. in the survey itself, simply random number generators
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
none
Sample size: planned number of observations
300-500 individuals, depending on prolific availability, with incomes of $100k or more
Sample size (or number of clusters) by treatment arms
none
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
UCLA
IRB Approval Date
2026-03-17
IRB Approval Number
IRB-26-0614
Analysis Plan

Analysis Plan Documents

Analysis Plan

MD5: de550ad0e30307419226619ce8ed26ad

SHA1: 28c33f7cb8c9311754fb0478f591d70e4c70086d

Uploaded At: March 31, 2026

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