Time perception and intertemporal choice

Last registered on April 08, 2021

Pre-Trial

Trial Information

General Information

Title
Time perception and intertemporal choice
RCT ID
AEARCTR-0007482
Initial registration date
April 07, 2021

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 08, 2021, 6:17 AM EDT

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

Locations

Region

Primary Investigator

Affiliation

Other Primary Investigator(s)

PI Affiliation
Harvard University
PI Affiliation
Bocconi University
PI Affiliation
Oxford University
PI Affiliation
Harvard University

Additional Trial Information

Status
In development
Start date
2021-04-08
End date
2021-07-31
Secondary IDs
Abstract
In this project, we use survey experiments to study whether and how time perception affects intertemporal choice and, in particular, hyperbolic-like behavior.
External Link(s)

Registration Citation

Citation
Bordalo, Pedro et al. 2021. "Time perception and intertemporal choice." AEA RCT Registry. April 08. https://doi.org/10.1257/rct.7482
Experimental Details

Interventions

Intervention(s)
Intervention Start Date
2021-04-08
Intervention End Date
2021-07-31

Primary Outcomes

Primary Outcomes (end points)
Share of patient choices
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Time perception (if elicited)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We conduct an online survey experiment on individual decision-making. The main feature of our experimental setup are multiple pairwise intertemporal choices that participants make after reading computerized instructions. In each intertemporal choice, subjects choose between a smaller Amazon gift card they receive sooner in time or a larger Amazon gift card they receive later in time. Between choices, we only vary the later date. This variation in the later date differs between treatments and allows us to test certain predictions that we state below and in our Analysis Plan.
Experimental Design Details
Experimental Design
Overview
We conduct an online survey experiment on individual decision-making. The main feature of our experimental setup are multiple pairwise intertemporal choices that participants make after reading computerized instructions. In each intertemporal choice, subjects choose between two Amazon gift cards, gift card A and gift card B. Each gift card consists of two components:
an observable value x;
a date t during which the gift card would be made available (via email) to subjects.
In all choices, the value of gift card A, x_a, the value of gift card B, x_b, and the date of gift card A, t_a, remain constant. Between choices, we vary only the date of gift card B, t_b. In addition, in each choice, we have x_a<x_b and t_a<t_b: gift card A is always the sooner-smaller alternative and gift card B is always the larger-later alternative.

In addition, we elicit from some subjects (depending on the treatment condition, see below) subjects’ perception of time regarding t_a and particular values of t_b. In doing so, we build on the method of (Zauberman, Kim, Malkoc, and Bettman, 2009, Journal of Marketing Research).

Treatments
Our treatments follow a 4x2 factorial design. In the first dimension of the design, we vary the value of t_b across four between-subjects treatments. In the second dimension, we vary whether subjects only make intertemporal choices or whether we elicit their time perception as well.

In all treatments, we set x_a= €70, x_b= €71, and t_a= 9 days. Between treatments, we set t_bequal to the following values in the order in which they are displayed:
Condition A: t_b equals 10 days, 20 days, 25, days, 30 days, 40 days, 45 days, and 50 days.
Condition B: t_b equals 50 days, 45 days, 40, days, 30 days, 25 days, 20 days, and 10 days.
Condition C: t_b equals 10 days, 11 days, 12, days, 13 days, and 50 days.
Condition D: t_b equals 50 days, 49 days, 48, days, 47 days, and 10 days.

Condition without time perception: Subjects only make the intertemporal choices.
Condition with time perception: In addition to the intertemporal choices, we elicit subjects’ time perception four times. In A-B, we elicit subjects’ time perception of t_a=9 days and t_b= 30 days after they made their fourth choice as well as their time perception t_a=9 days and t_b= 50 in A, = 10 in B after they made their final choice. In C-D, we elicit subjects’ time perception of t_a=9 days and t_b= 10 in C, =50 in D days after they made their first choice as well as their time perception t_a=9 days and t_b= 50 in C, = 10 in D after their final choice.
Outcome variables
In conditions A and B, we are interested in subjects’ choices with t_b=20,25,30,40.
In conditions C and D, we are interested in subjects’ choices with t_b=10,50.
If we elicit time perception, we are interested in the within-subject differences between subjects’ time perception of t_a and t_b after their fourth choice as well as the within-subject differences between t_a and t_b after subjects’ final choice.
Hypothesis and Tests
In all conditions with and without time perception elicitation, we test whether more subjects choose patiently (ie, gift card B) in A than in B and whether more subjects choose patiently (ie, gift card B) in D than in C.
In the conditions with time perception, we test whether the difference between t_a=9 and t_b= 30 is greater in B than in A, whether the difference between t_a=9 and t_b= 10 is greater in C than in D, and whether t_a=9 and t_b= 50 is greater in C than in D.

Exclusion criteria
We consider two samples. First, we consider all subjects who participated in our experiment. Second, we consider subjects who passed our attention checks (see below), made consistent choices (ie whenever they were patient for some value of t_b they are not impatient for any smaller values of t_b, or whenever they were impatient for some value of t_b they are not patient for any greater values of t_b), and spend a reasonable amount of time completing the experiment.
The attention check refers to the following task each subject performs during the experiment. On each decision screen, we ask subjects to type the values of t_a and t_b of the current choice options into respective text fields. Subjects can type into these text fields anything. Subjects pass our attention check if they state the actual values of t_a and t_b of the current choice options. Subjects who make a mistake for at least one of these values fail our attention check.

Randomization and sample size
Subjects are randomly assigned to one of 4x2 (between-subjects) treatments. We aim for 825-875 subjects per treatment
Randomization Method
Randomization done by a computer
Randomization Unit
Individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
825-875 subjects per treatment
Sample size: planned number of observations
825-875 subjects per treatment
Sample size (or number of clusters) by treatment arms
825-875 subjects per treatment
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
Harvard University-Area Committee on the Use of Human Subjects
IRB Approval Date
2020-03-06
IRB Approval Number
IRB19-1719
Analysis Plan

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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