Evaluating the impact of discount vouchers on the adoption of disease-free shrimp larvae in Bangladesh

We will introduce discount vouchers for the shrimp farmers as the intervention. These vouchers will be distributed among randomly selected subsets of shrimp farmers so that they can purchase the specific pathogen-free (SPF) post-larvae (PL) to produce shrimp. About one-third of the sample will receive a discount voucher to buy the first specified units of specific pathogen-free (SPF) shrimp post-larvae (PL) at the market price of the normal hatchery PL (the benchmark). We call this group the treatment group A. Another one-third of the sample (treatment group B) will receive a discount equal to half the discount received by treatment group A to buy the first specified units of the SPF-PL. The rest will be a control group. The highest amount to be purchased with the voucher and the exact monetary values of the discount vouchers are being determined based on the data from the previous rounds and discussions with the stakeholders.

2024-06-09

2024-09-30

We consider the following as the primary outcomes:
(1) Intention to treat (TT) analyses:

(i) Purchasing SPF-PL (1/0): We define the purchase of SPF-PL as binary for each individual (1/0), in the stocking period after the distribution of the vouchers
(ii) Quantity of the SPF-PL purchased: We use the total amount of purchased SPF-PL in the stocking period after the distribution of the vouchers.
(iii) Plan to purchase the disease-free PL in the next production cycle: We define the binary outcome variable as 1 when the farmer plans to purchase the SPF-PL in the next production cycle.

(2) Local Average Treatment Effect (LATE) analyses:

(i) Mortality: We define mortality as binary if an individual farmer experiences any mortality in the stocking period after the distribution of the voucher.
(ii) Percentage of mortality: We define this as the percentage of overall mortality in the pond in the stocking period after the distribution of the voucher.
(iii) Monetary loss: We measure the approximate losses in BDT in the stocking period after the distribution of the voucher.
(iv) Gross value of shrimp output produced: We measure the gross value of the shrimp output in terms of BDT in the stocking period after the distribution of the voucher.
(v) Weight of harvested shrimp: We define it in terms of the kilogram quantity of shrimps harvested in the stocking period after the distribution of the voucher.

(vi) Food Insecurity Experience Scale (FIES) score: We will use the FIES score generated using the widely used Household Food Insecurity and Access Score (HFIAS)

The study will evaluate the impact of discount vouchers at different levels in the context of shrimp farming in the Southern region of Bangladesh. The International Food Policy Research Institute (IFPRI), Michigan State University, WorldFish, and Alliance Bioversity-CIAT are collaborating on this experiment. This study will use a sample of shrimp farmers to conduct a randomized controlled trial (RCT).

There is an existing sample of 1222 shrimp farmers in the southern region of Bangladesh from a study conducted by the International Food Policy Research Institute (IFPRI). IFPRI is conducting a second round of surveys from May 2024 to collect information on demographic characteristics, production, and farming practices. This survey is taking place in the comfort of the subject's home or farm.

After this survey, discount vouchers will be distributed among randomly selected subsets of shrimp farmers so that they can purchase the specific pathogen-free (SPF) post-larvae (PL) to produce shrimp. About one-third of the sample will receive a discount voucher to buy the first specified units of specific pathogen-free (SPF) shrimp post-larvae (PL) at the market price of the normal hatchery PL (the benchmark). We call this group the treatment group A. Another one-third of the sample (treatment group B) will receive a discount equal to half the discount received by treatment group A to buy the first specified units of the SPF-PL. The rest will be a control group. The highest amount to be purchased with the voucher and the exact monetary values of the discount vouchers are being determined based on the data from the previous rounds and discussions with the stakeholders.

Randomization done in office by a computer

Randomization is clustered at the level of “cluster of farmers”.
Note that priorly, three specific group of interventions were introduced among the shrimp farmers in the Southern region of Bangladesh. These interventions can broadly fall under different cluster participation programs which are being implemented by: (1) the Department of Fisheries, Government of Bangladesh (under the World Bank-funded Sustainable Coastal and Marine Fisheries Project [SCMFP]), henceforth DoF; (2) ACI Agrolink Ltd., henceforth ACI; and (3) the Bangladesh Shrimp and Fish Foundation (BSFF). These three represent diverse actors, including government, private sector processor cum input firm, and industry advocacy body.
In our current study, a cluster of farmers is a group of farmers defined in the following manner. In each cluster, we have three types of randomly selected shrimp farmers:
(i) farmers who have formed a group based on either DoF-prescribed guidelines or ACI/BSFF-prescribed guidelines where they farm in contiguous ponds. We can say that these farmers participate in one of the cluster participation programs introduced by the entities mentioned above.
(ii) farmers of the same village who do not participate in the cluster participation programs,
(iii) farmers who farm in an adjacent village and do not participate in the cluster participation programs.

Yes

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1222 shrimp farmers

24 clusters in control, 22 clusters in treatment group 1, and 22 clusters in treatment group 2