AEA RCT Registry

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Nudging Take-up of $1 Health Insurance Plans

Last registered on January 21, 2021

View Trial History

Pre-Trial

Trial Information

General Information

Title

Nudging Take-up of $1 Health Insurance Plans

RCT ID

AEARCTR-0007022

Initial registration date

January 14, 2021

Last updated

January 21, 2021 3:23 PM EST

Location(s)

Country

United States of America

Region

California

Primary Investigator

Name

Andrew Feher

Affiliation

Covered California

Contact Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Status

In development

Start date

2021-01-20

End date

2021-01-31

Keywords

Behavior, Health

Additional Keywords

choice errors, Affordable Care Act, field experiment

JEL code(s)

Secondary IDs

Abstract

With the termination of Cost-Sharing Reduction (CSR) subsidies in 2017, many individuals in California's ACA Marketplace became eligible for $1 plans. But not all individuals eligible for $1 plans select the most generous coverage option for which they're eligible, thereby enrolling in a low actuarial value plan when a higher actuarial value plan is available for the same (or lower) price.

This project's goal is to examine whether an informational email can increase $1 CSR Silver take-up among Covered California households enrolled in Bronze, Gold or Platinum plans for the 2021 coverage year.

Choice errors are common across different health insurance markets--including Medicare, employer-sponsored insurance and the ACA Marketplaces--and thus identifying ways to improve choice quality is of interest to policymakers both in California and nationwide.

External Link(s)

Registration Citation

Citation

Feher, Andrew. 2021. "Nudging Take-up of $1 Health Insurance Plans." AEA RCT Registry. January 21. https://doi.org/10.1257/rct.7022-1.3.

Sponsors & Partners

Experimental Details

Interventions

Intervention(s)

The intervention centers on $1 CSR Silver-eligible members who selected a Bronze, Gold or Platinum plan during the 2021 Open Enrollment period. In the final weeks of the Open Enrollment period, these Covered California members will receive an email nudge that encourages them to switch metal tiers (from Bronze, Gold or Platinum to CSR Silver) so as to pay less when accessing care. They are further encouraged to take action by 1/31/2021, the end of the 2021 Open Enrollment period.

Intervention Start Date

2021-01-20

Intervention End Date

2021-01-31

Primary Outcomes

Primary Outcomes (end points)

Our primary outcome will be an indicator for whether a household enrolled in a CSR Silver plan for the 2021 coverage year by the end of the Open Enrollment period.

Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)

Secondary outcomes include net premium and calls to Covered California's Service Center.

Secondary Outcomes (explanation)

Experimental Design

This is a 2-arm block randomized design. The two blocks are (1) $1/month Silver 87-eligibles in Bronze or Gold plans and (2) $1/month Silver 94-eligibles in Bronze, Gold or Platinum plans.

Within each block, households are randomly assigned to one of two arms: (1) a control group or (2) an informational email group.

Experimental Design Details

Randomization Method

We used Stata to carry out the randomization.

Randomization Unit

Random assignment occurs at the household-level.

Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters

N/A

Sample size: planned number of observations

Approximately 5,600 households

Sample size (or number of clusters) by treatment arms

Approximately 50% of households were assigned to a control group and the remaining 50% were assigned to the informational email.

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

To arrive at an estimate for the minimum detectable effect (MDE)—and given that enrollees have a little more than one week to take action—we assume a baseline metal tier switch rate of 5 percent. In a pairwise comparison, we’d be powered at the 80% level to detect a 1.8 percentage point difference in Enhanced Silver enrollment rates.

Supporting Documents and Materials

IRB

INSTITUTIONAL REVIEW BOARDS (IRBs)

IRB Name

California Health and Human Services Agency Committee for the Protection of Human Subjects

IRB Approval Date

2021-01-21

IRB Approval Number

N/A

Analysis Plan

Analysis Plan Documents

Pre-analysis plan