The Impact of Group Commitment Contracts on Smoking Cessation and Weight Loss

Summary

We will conduct a randomized controlled trial to evaluate the effectiveness of group commitment contracts for smoking cessation and weight loss.

Conditions

• Smoking Cessation
• Weight Loss

Interventions

BEHAVIORAL

Group Commitment Contract

A group contract where the primary individual, who will be tracked by the study, can invite peers to join the contract and form their group. To initiate a contract, a user must choose: the stakes, start date, and (for weight loss contracts) target weight, and and, optionally, to allow other members to have the power to invite other people to join the group.

BEHAVIORAL

Individual Monetary Rewards

Individuals eligible for a $100 monetary reward (incentive) following verified smoking cessation or weight loss.

BEHAVIORAL

Individual Commitment Contract

Individuals will have the opportunity to create an individual commitment contract to quit smoking. They will have the option to set the stakes, start date, and (for weight loss contracts) target weight.

OTHER

Information

In the initial survey, participants will receive additional information treatments on the likelihood of success of the different incentives and contracts, with the goal of shifting "naives" to "sophisticates."

Sponsors & Collaborators

• Northwestern University

  collaborator OTHER

• National Bureau of Economic Research, Inc.

  lead OTHER

Principal Investigators

• Dean Karlan, PhD · Northwestern University

• Anna Tuchman, PhD · Northwestern University

• Jonathan Zinman, PhD · Dartmouth College

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2023-12-18

Primary Completion

2025-06-19

Completion

2025-06-19

Countries

• United States

Study Locations