Can discounted transit improve mobility and well-being for lower-income residents?

Last registered on March 30, 2023


Trial Information

General Information

Can discounted transit improve mobility and well-being for lower-income residents?
Initial registration date
March 27, 2023

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
March 30, 2023, 3:36 PM EDT

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


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Primary Investigator

The Lab @ DC

Other Primary Investigator(s)

PI Affiliation
The Lab @ DC
PI Affiliation
The Lab @ DC
PI Affiliation
The Lab @ DC
PI Affiliation
The Lab @ DC

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
The cost of transportation can present challenges for low-income Washingtonians: making it harder to get a job, maintain a job, access social services, obtain healthcare, and care for their families. Building on the District’s efforts to address cost as a barrier to transit equity—such as Mayor Muriel Bowser’s 2019 Free Circulator trial and Kids Ride Free program—the District of Columbia government and the Washington Metropolitan Area Transit Authority are conducting a randomized evaluation of free and discounted transit fares. We will measure the impact of transit cost on low-income residents’ mobility, employment, and well-being. The findings may help shape initiatives to make public transit more affordable to low-income residents.

Registration Citation

Crum, Jack et al. 2023. "Can discounted transit improve mobility and well-being for lower-income residents?." AEA RCT Registry. March 30.
Sponsors & Partners


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Experimental Details


LIFT study-specific SmarTrip cards—Metro's payment technology for bus and rail—were programed with 9 months of the relevant discounts, then provided to residents according to their assigned group. Residents assigned to get no discounts on transit did not get a SmarTrip card from LIFT. Regardless of their assigned group, everyone who applied to LIFT and was deemed eligible will get a $25 Visa gift card. Residents in the treatment groups were directed to pick up their LIFT study-provided SmarTrip cards at WMATA’s Transit Accessibility Center from January 27 through February 24, 2023. In-person pick-up was the sole way for residents in the two treatment groups to get their study-provided SmarTrip cards until the end February 2023. We set the deadline for the pick-up period based on the expected pace of pickup; based on budget, our goal was for no more than 500 LIFT SmarTrip cards to require mailing (which was more time and resource intensive). For the cards remaining after the pickup deadline was passed, we mailed the cards to study participants on March 13, 2023.

The discounts will work when participants pay their fare on Metrobus, Metrorail, DC Circulator, and other regional bus partners in Maryland and Virginia. Those regional bus partners include Arlington Transit (ART), the City of Fairfax-University Energysaver Bus System (CUE), the Driving Alexandria Safely Home (DASH), the Fairfax Connector, TheBus in Prince George’s County, and Ride On buses in Montgomery County.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
1) Average number of public transit trips taken per month as measured by administrative data from SmarTrip cards
2) Proportion of months during the study that an individual was employed
3) Self-reported transportation security at the end of study: Survey-based index of six questions related to transportation security
4) Self-reported overall well-being at the end of study: Survey-based responses to the Cantril Ladder
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
LIFT offers two different levels of transit discounts to low-income DC residents. We have enrolled 2,411 eligible residents and randomly assigned them to one of three groups: 1) free, unlimited trips; 2) a half-price discount on transit; or 3) no discount on transit.
Experimental Design Details
Not available
Randomization Method
Randomization done in office by a computer
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
0 clusters
Sample size: planned number of observations
2,411 individuals
Sample size (or number of clusters) by treatment arms
588 individuals were assigned to receive free unlimited trips; 783 individuals were assigned to receive half-price discounts; and 1,040 individuals were assigned to receive no discounts.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
University of Maryland, College Park IRB
IRB Approval Date
IRB Approval Number
Analysis Plan

Analysis Plan Documents

LIFT Pre-Analysis Plan 2023

MD5: 6045b8d65fbd7aab6baae4be28c8be84

SHA1: f9eb3968c363bfcb7d626063223957f8fdedfd1e

Uploaded At: March 23, 2023