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Complementarities of Irrigation and Extension Services in Nepal
Initial registration date
December 13, 2016
December 14, 2016 10:58 AM EST
Other Primary Investigator(s)
Additional Trial Information
Governments in developing countries and international agencies supporting them often employ two strategies to try to improve agricultural production. First, they invest in major public works projects such as irrigation schemes. Second, they organize extension services to try to improve the agricultural methods and technologies used by individual farmers, including those who benefit from irrigation projects. This project aims to study the relative importance of these two strategies in improving agricultural livelihoods and especially the prospective complementarity of these two strategies. We hypothesize that changes in the water resource environment brought on by irrigation improvements (or, similarly, changing water availability due to climate change) may prompt farmers to become more responsive to trying new agricultural methods, making extension and irrigation improvements more effective when they are combined with each other. We propose to study the effectiveness of these two strategies in the context of Nepal, where the World Bank and the Government of Nepal are supporting modernization of a large-scale irrigation works program alongside agricultural extension. This research will answer policy relevant questions about how to maximize public investments in agriculture, as well as behavioral questions about how farmers make decisions about adapting to changing environments.
We have three primary evaluation questions: 1. What is the impact of agricultural extension service provision of crop choice, yields and household welfare? 2. What is the impact of modernized irrigation infrastructure on crop choice, yields and household welfare? 3. What is the impact of both extension services and modernized irrigation infrastructure on crop choice, yields and household welfare?
The third evaluation question is the most original, and addresses issues of whether changing environments prompt farmers to take notice of extension programs and whether timely extension services can maximize adaptation in response to changing environments. We plan to assess this question through the interaction of two interventions, randomized agricultural extension programs and non-randomized placement of modernized irrigation systems. Groups of farmers who have been organized into training sessions will be randomly assigned to complete training in groups of 2 per year. We expect the irrigation system to differentially impact farmers living in different parts of the scheme with the primary difference being whether the farmer lives in the upstream or the downstream of existing canals. We can use differences in differences across upstream and downstream farmers to assess changes associated with irrigation and randomized timing of extension to assess changes resulting from irrigation. The randomization of extension will be stratified by upstream and downstream farmers to allow assessing the interaction of the two, the primary outcome of interest.
The ultimate outcome of interest both for irrigation, extension, and the interaction is improvement in farmer’s agricultural revenue. We will assess this outcome for at least one full year prior to the completion of the irrigation scheme and one full year following with a prospective second follow-up year pending constitution of the project’s interventions. Additional immediate outcomes will include farmers’ attendance in trainings and knowledge after extension programs as well as social learning across groups to assess mechanisms.
Intervention Start Date
Intervention End Date
Primary Outcomes (end points)
Adoption of new agricultural technologies, agricultural income
Primary Outcomes (explanation)
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Agricultural extension training is rolled-out randomly amongst farmer groups. The irrigation intervention involves a quasi-random design.
Experimental Design Details
Randomization done on a computer from the list of farmer's groups.
Was the treatment clustered?
Sample size: planned number of clusters
60 farmer groups
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
Because the project can only conduct trainings with 20 farmers groups in a year, we are limited to treating only 20 groups per year or 60 in a three year period. The power calculations give a minimum detectable effect on the variable of interest on the comparison between any one of the following six groups with the others:
1. Groups who are affected by irrigation (top of canal) who receive training before irrigation starts
2. Groups who are not affected by irrigation (bottom of canal) who receive training before irrigation starts
3. Groups who are affected by irrigation (top of canal) who receive training after irrigation starts
4. Groups who are not affected by irrigation (bottom of canal) who after training before irrigation starts
5. Groups who are affected by irrigation (top of canal) who do not receive training
6. Groups who are not affected by irrigation (bottom of canal) who do not receive training For example, the primary effect of interest is that of getting the training in an irrigation affected area after the irrigation improvements have begun. Since 1/6 of the 60 groups will be in this category, for the purpose of the power calculations, 16.67% of households are considered “treated.”
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
INSTITUTIONAL REVIEW BOARDS (IRBs)
University of California, San Diego
IRB Approval Date
IRB Approval Number
Post Trial Information
Is the intervention completed?
Is data collection complete?