Sanitation and Welfare: Evidence from a Natural Experiment in Panama

Last registered on June 19, 2017

Pre-Trial

Trial Information

General Information

Title
Sanitation and Welfare: Evidence from a Natural Experiment in Panama
RCT ID
AEARCTR-0002268
Initial registration date
June 19, 2017

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 19, 2017, 3:53 PM EDT

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

Locations

Region

Primary Investigator

Affiliation
CAF - Development Bank of Latin America

Other Primary Investigator(s)

Additional Trial Information

Status
On going
Start date
2017-04-01
End date
2018-06-30
Secondary IDs
Abstract
What are the effects of sanitation interventions on welfare? Every year, thousands of citizens in developing countries die as a consequence of poor water and sanitation conditions. This situation is particularly harsh for young children and newborns, as acute diaharreal disease has huge negative consequences on this population. Consequently, estimating the effects of interventions on sanitation infrastructure on health and other welfare conditions of poor households is crucial, in order to determine the effectiveness of these programs. We exploit a potential natural experiment that took place in Panama recently. The San Miguelito project is a huge sanitation infrastructure intervention, in which thousands of households in Panama City's poorest district get access to the sewage system. However, planning and execution errors imply that certain sectors of the district are no included in the project, leaving a big number of houses, comparable to those that will be treated, out of the intervention. After checking if there is balance between treatment and control groups, and adjusting for any imbalances between them, we will exploit this natural experiment through a difference in differences estimation, to determine the impact of the San Miguelito project on several welfare and health indicators, including prevalence of parasites on stool samples for children below 5 years. To account for potential spillover effects, we also include a distant control group, composed of households living in a different district far away of San Miguelito, but that shares similar socioeconomic characteristics. We hypothesize that the intervention has positive effects on several health and anthopometric indicators, such as diarrhea disease on young children, weight and height, and in other important dimensions, such as school attendance, productivity, or psychological health.
External Link(s)

Registration Citation

Citation
CAF, Pilar. 2017. "Sanitation and Welfare: Evidence from a Natural Experiment in Panama." AEA RCT Registry. June 19. https://doi.org/10.1257/rct.2268-1.0
Former Citation
CAF, Pilar. 2017. "Sanitation and Welfare: Evidence from a Natural Experiment in Panama." AEA RCT Registry. June 19. https://www.socialscienceregistry.org/trials/2268/history/18819
Experimental Details

Interventions

Intervention(s)
Intervention Start Date
2017-04-01
Intervention End Date
2018-06-30

Primary Outcomes

Primary Outcomes (end points)
Health indicators, anthopometric measures, school attendance, productivity, psychological health, sexual and reproductive rights
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The ideal evaluation design would consist of randomizing the access to the sewage system. This would assure comparability between households with and without access, and lead to a robust impact estimation of the intervention. Nevertheless, operative, logistical, and ethical reasons make this design unfeasible in this context.

On the other hand, this project can be considered as a natural experiment due to some of its particular characteristics, although available information as of now is not completely certain on this matter. The selection criteria used to determine the intervention places and coverage zones were associated with geographical and spatial features related to the San Miguelito basins. Therefore, the absence of differences in health and community welfare dimensions between treated and control households would not be surprising. If this were the case, a comparison of both household groups before and after the intervention would lead to reliable impact estimators.

Nonetheless, both groups could differ in observable and unobservable characteristics that could affect outcomes in health and welfare, which would hinder the identification of causal effects. Balance testing on observable characteristics using information produced by the baseline will help determine whether or not these differences exist. The presence of balance would ratify the existence of a natural experiment.

On the contrary, if balance between both groups does not exist, quasi-experimental techniques should be employed for impact calculation. In this particular case, the combination of matching and difference-in-differences methods would be suggested. In this scenario, the information collected in the baseline is useful to determine which households in the control group possess characteristics more closely related to those of the treatment group. Among the different matching techniques available, Propensity Matching Score, Balance-Sample Size Frontier Matching, and Genetic Matching are the most distinguished. Besides, the nature of this intervention makes it reasonable to use other impact evaluation techniques, such as a Geographic Regression Discontinuity or Instrumental Variables. Once household matching is accomplished, a difference-in-differences model would compare variations in outcomes on both groups.

In addition, taking into account possible spillover effects, an alternative control group was established using households located in the Panama North District, which is located far away from San Miguelito but shares similar sociodemographic characteristics. The same difference-in-differences and matching approach would be used to compare outcomes in both control groups to quantify the spillover effect.
Experimental Design Details
Randomization Method
No
Randomization Unit
No
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
No
Sample size: planned number of observations
2505 households
Sample size (or number of clusters) by treatment arms
835 households for treatment group, 835 for San Miguelito control group, 835 for Panama Norte control group
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
Hospital del NiƱo
IRB Approval Date
2017-01-05
IRB Approval Number
CBIHN-M-201701-002
Analysis Plan

Analysis Plan Documents

Sanitation and Welfare: Evidence from a Natural Experiment in Panama Pre-Analysis Plan

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials