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The effect of Self-Control on Debt Taking
Initial registration date
December 16, 2019
December 17, 2019 10:48 AM EST
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Other Primary Investigator(s)
Additional Trial Information
This experiment aims to study the link between self-control and consumption financed through debt taking. During the experiment participants perform an ego-depletion task during which they have to cross out letters. The ego depletion task is followed by a round during which participants can buy drinks on loan. Both the ego-depletion task and the shopping task are repeated twice. In the first shopping round the loan charges 20% interest and in the second round 10%. In addition to measuring borrowing, we also perform manipulation checks to test if our treatment had the desired effect.
There are two treatments:
(i) Treatment group – performs an ego deleting task during which they have to cross out the letter ‘e’ for three minutes, followed by a having to cross out the letter ‘e’, but only if it is not followed or preceded by a vowel according to a given rule for 10 Minutes. (ii) Control group – performs an ego depleting task during which they have to cross out the letter ‘e’ for three minutes, followed by having to cross out the letter ‘e’ for 10 Minutes.
Intervention Start Date
Intervention End Date
Primary Outcomes (end points)
There are three outcome variables:
1. Debt taken in shopping round 1 – we will test if participants in the treatment group that are ego-depleted are more likely to buy hot drinks in the first shopping round.
2. Debt taken in shopping round 2 – we will test if participants in the treatment group that are ego-depleted are more likely to buy hot drinks in the second shopping round.
3. Manipulation check – we will test if participants in the treatment group are more likely to report that they are tired, had to concentrate, are more likely to pick an easy puzzle, and perform worse in cognitive tasks.
Primary Outcomes (explanation)
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
1) There is a round during which participants perform the ego-depletion task. Both treatment and control group cross out the letter ‘e’ for three minutes. Following this the control group carries on crossing out the letter ‘e’, whilst the treatment group crosses out the letter e, but not it is preceded or followed by a vowel according to a given rule. This is designed to make the treatment group ego depleted and so reduce their self-control.
2) This round is followed by a manipulation check.
3) This task is followed by a shopping round during which participants can buy hot drinks on loan. The room is artificially cooled down to make hot drinks more appealing. As participants have not earned any money at this point, they can only buy the drinks on loan. Purchase options are advertised with prices and current loan costs. Participants are informed that they will receive free tap water if no purchase is made. Participants are thus unaware who makes purchases and who does not within the laboratory environment. These three stages are repeated twice. The interest rate on the loan in higher in round 1 than in round 2. Participants are informed about this in advance in the experimental instructions.
Experimental Design Details
Was the treatment clustered?
Sample size: planned number of clusters
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
120 – Treatment Group
120 – Control Group
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
INSTITUTIONAL REVIEW BOARDS (IRBs)