Strategic Ignorance of Risk — Its Causes and Policy Consequences

Last registered on April 17, 2018

View Trial History

Pre-Trial

Trial Information

General Information

Title

Strategic Ignorance of Risk — Its Causes and Policy Consequences

RCT ID

AEARCTR-0002902

Initial registration date

April 16, 2018

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 17, 2018, 4:20 PM EDT

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

Locations

Country

Denmark

Region

Primary Investigator

Name

Jonas Nordstrom

Affiliation

University of Copenhagen

Contact Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Status

Completed

Start date

2015-04-09

End date

2015-06-26

Keywords

Health

Additional Keywords

Risk, Ignorance, Calories

JEL code(s)

Secondary IDs

Abstract

We examine the causes and policy consequences of strategic (willful) ignorance of risk as an excuse to overengage in risky behavior. In an experiment on Copenhagen adults, we allow subjects to choose whether to learn the calorie content of a meal before consuming it, and
measure their subsequent calorie intake.

External Link(s)

Registration Citation

Citation

Nordstrom, Jonas. 2018. "Strategic Ignorance of Risk — Its Causes and Policy Consequences." AEA RCT Registry. April 17. https://doi.org/10.1257/rct.2902-1.0

Former Citation

Nordstrom, Jonas. 2018. "Strategic Ignorance of Risk — Its Causes and Policy Consequences." AEA RCT Registry. April 17. https://www.socialscienceregistry.org/trials/2902/history/28458

Sponsors & Partners

Experimental Details

Interventions

Intervention(s)

Intervention Start Date

2015-04-09

Intervention End Date

2015-06-26

Primary Outcomes

Primary Outcomes (end points)

Strategic (willful) ignorance of calorie information.
Calorie consumption.
Expected number of calories in the chosen meal.
All measured at the individual level.

Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)

Secondary Outcomes (explanation)

Experimental Design

We recruited 201 subjects from the general population in the Copenhagen area to participate in an hour-long experiment session. Participants were paid DKK 300 (around USD 50).

Our experimental design builds on that in Thunström et al. (2016). The experiment uses ready meals as the risky good. Ready meals are ideal for our purposes, since they are fairly transparent in immediate pleasure (taste), but non-transparent in future harm (calories). Ready meals thus provide scope for ignoring information about the harm from consumption.

All subjects were offered a choice between two meals: chicken with salad and pasta (500 calories), or roast beef with salad and quinoa (890 calories). Subjects were informed that one of the meals was high-calorie and the other meal low-calorie, and were told the specific calorie numbers, but not initially which meal was which.

The experiment was conducted in seven steps:
Step 1: Subjects rated the expected taste of both meals.
Step 2: Subjects chose their preferred meal.
Step 3: The 96 subjects in the treatment group were given the opportunity to learn the meals’ calorie content by choosing to open an envelope containing the information. If they did not want to know the calorie content of the meals, they opened another envelope that contained an empty sheet of paper. The 53 subjects in the control informed group were told the meals’ calorie content both verbally and on paper. The 52 subjects in the control uninformed group were told nothing about the specific meals’ calorie content.
Step 4: Subjects in the treatment and control informed groups were offered the opportunity to revise their meal choice.
Step 5: Subjects finished their meal while answering survey questions.
Step 6: Subjects were weighed and measured, and their leftover food weighed to determine their calorie consumption.

Experimental Design Details

Randomization Method

Randomization done in office by a lottery.

Randomization Unit

Individual

Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters

Two control groups, one treatment group.

Sample size: planned number of observations

204 subjects.

Sample size (or number of clusters) by treatment arms

Subjects would be distributed over control and treatment groups as follows.
51 subjects in the control informed group
51 subjects in the control uninformed group
102 subjects in the treatment group. Subjects given the opportunity to learn the meals’ calorie content.

Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Supporting Documents and Materials

IRB