Non-Take Up in Social Programs: Evidence from a Randomized Controlled Trial

Last registered on June 28, 2023


Trial Information

General Information

Non-Take Up in Social Programs: Evidence from a Randomized Controlled Trial
Initial registration date
June 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
June 28, 2023, 5:11 PM EDT

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



Primary Investigator

Bank of Spain

Other Primary Investigator(s)

PI Affiliation
PI Affiliation

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
We study the drivers of non take-up (NTU) in social programs, focusing on the Spanish Minimum Income Scheme (Ingreso Mínimo Vital, IMV), a program that guarantees every household a minimum income. Around 57% of households that could access the IMV have not applied for it. Previous literature suggests that this could be due to a lack of awareness of the regulation, not recognizing oneself as a possible recipient, the lack of proximity to the corresponding administration, stigmatization, socio-economic or socio-cultural barriers such as linguistic or digital divide, or participation in the informal economy and a related mistrust of contacting public authorities in this situation. In this paper, we seek to understand the main factors that determine the phenomenon of NTU. The randomized control trial will allocate 400 neighborhoods in Spain to one of the following possible treatments: an in-person intervention, a social media intervention, or both. A fourth group will serve as pure control. Interventions provide information on the existence of the program and requirements to apply and provide support with the application process. We expect the interventions to decrease NTU, reduce poverty, and increase trust in public administrations.
External Link(s)

Registration Citation

Domenella, Yanina, Monica Martinez-Bravo and Carlos Sanz. 2023. "Non-Take Up in Social Programs: Evidence from a Randomized Controlled Trial." AEA RCT Registry. June 28.
Sponsors & Partners

There is information in this trial unavailable to the public. Use the button below to request access.

Request Information
Experimental Details


This RCT will evaluate the effectiveness of two different treatments to address NTU:
1. In-person Intervention: there will be a number of outreach in selected neighborhoods which include awareness activities of the benefit as well as searching for potential beneficiaries of the benefit. There will also be advisory services to assist with the application of the benefit.
2. Social Network Campaign: there will be a campaign through Facebook and Instragram to raise awareness of the benefit and to encourage applications.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Our main outcomes will be the number of new applications to the benefit measured at the aggregate (node) level, the general opinion of residents about the benefit, and the level of trust in institutions. The last two outcomes would be examined at the individual level on the anonymized dataset.
Primary Outcomes (explanation)
The description of these outcomes, hypothesis and data source can be found in the Pre-Analysis Plan.

Secondary Outcomes

Secondary Outcomes (end points)
• Financial situation: income, “capacity to pay bills by the end of the month”.
• Knowledge and opinion of the benefit.
• Trust in public administrations, and capacity of political institutions to address citizens’ main problems.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The unit of randomization is the census tract ( which we refer as the node). Each of the 400 nodes was randomly assigned to one of the following groups: (1) group 1 (G1 from now on), receiving in-person intervention (n=100); (2) group 2 (G2), receiving social media intervention through Facebook and Instagram (n=100); (3) group 3 (G3), receiving both interventions (i.e., in-person and via social media) (n=100); and group 4 (GC), receiving none (pure control group) (n=100). In addition to this, nodes assigned to the social media intervention (G2 and G3) are then randomly assigned to one of 2 groups (GA or GB), that differ in the order they will receive each of the 3 social media ads.
Experimental Design Details
The units of analysis in this RCT are census tracts (secciones censales) in Spain. As a first step to select which census tracts would participate in the experiment, EAPN-ES chose 510 census tracts with high shares of low-income population and that had the appropriate facilities and network of collaborators for the intervention to operate. To verify the first criterion, the partner used information from the Spanish National Statistics Institute regarding the percentage of households with income below 40% of the median income residing in each census tract (40% of the median household median income corresponds to approximately to 535 euros a month in 2020). To verify the second criterion, the partner consulted through their network of NGOs if they had a local NGO or organization that could lend appropriate facilities to conduct the intervention. In particular, some indoor private office space to help with the applications was necessary. Note that, while the presence of local organizations was important, the treatment was provided in a centralized manner by the partner organization EAPN-ES. We provide more details on this below.
Those facilities were referred as “contact point”, and they are typically within the census tract of study or near them. A contact point could be, for example, a social center, a day center, a soup kitchen, an association, a reception center, or a homeless shelter. In this project, each census tract selected is called a “node” and each contact point is the “point”. As will be explained in the description of the interventions, the node becomes the relevant unit for the outreach campaign, as it is where posters will be placed, and flyers distributed. However, the counseling and support for applying to the benefit was conducted at the point. In the case of the social media intervention, the treatment is done at the zip code level corresponding to the node.
The research team in collaboration with the Ministry did the second step to select 400 nodes out of the initial 510 nodes proposed by the partner. We visualized the nodes and points in a map and eliminated from the initial proposal those that were in proximity in order to minimize the risk of contamination. Finally, EAPN-ES further eliminated some additional nodes whose distribution across the regions was complicated for logistical reasons. The final sample of 400 nodes is at least 300 meters of distance from any other node and they do not share the same postal code as any other node.
Randomization Method
Stratified randomization at the neighborhood level. See the document of the Pre-Analysis Plan for more details.
Randomization Unit
Randomization was done at the node (i.e., census tract) level.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
400 census tracts (nodes)
Sample size: planned number of observations
12,000 respondents of surveys and 400 observations for aggregate-level statistics from administrative data.
Sample size (or number of clusters) by treatment arms
100 nodes by each of the 4 study arms
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
The Principal investigators conducted power calculations on two outcomes: total number of applications and satisfaction with the benefit. For the first outcome, we considered the standardized variable, so that we assumed a control group’s mean of 0 and standard deviation (SD) of 1. For the second variable, we used the replies to the question “What is your opinion about the IMV?”, collected during the second wave of surveys done by Martinez-Bravo and Sanz (2021) in November 2020. The scale of answers go from 0 (“I totally dislike it”) to 10 (“I totally like it”). We considered a mean satisfaction for the control group of 5.83 and SD of 3.03. In addition to these main assumptions, we considered a significance level of 0.05, an intra-cluster correlation of 0.5, 100 clusters per treatment arm, and an average cluster size of 30. In the 1x1 comparisons (e.g., when trying to estimate the impact of in-person or on-line interventions comparing outcomes with that of the control group), we will be powered at the 80% to detect a minimum effect of 0.28 SD. In the case of satisfaction, we would be able to detect effects of 0.86 or larger (equivalent to a treatment group satisfaction of 6.69 or larger). In the specification where we combine our three treatment groups into a single group, we considered for power calculations 100 clusters in the control group, and 300 clusters in the treatment group. In this case, still considering a power of 80%, we would be able to detect a minimum effect of 0.23 SD of the number of applications, and a minimum change in the level of satisfaction of 0.7. It is important to note that these calculations are conservative since they do not take into account the fact that randomization was stratified. In addition to this, in the diff-in-diff and ANCOVA specifications, we will consider information from the baseline survey which will allow to increase power (or, equivalently, reduce the minimum detectable effects for the given power).

Institutional Review Boards (IRBs)

IRB Name
Comité Ético vinculado a los itinerarios de inclusión social de la Secretaría General de Objetivos y Políticas de Inclusión y Previsión Social
IRB Approval Date
IRB Approval Number
Favorable evaluation from the Ethics Committee of the Ministry of Social Inclusion, dated February 22, 2023.
Analysis Plan

There is information in this trial unavailable to the public. Use the button below to request access.

Request Information


Post Trial Information

Study Withdrawal

There is information in this trial unavailable to the public. Use the button below to request access.

Request Information


Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials