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

All the participant farmers in this study will receive one information card that will provide information on SPF-PL, its advantages in reducing white-spot disease in the pond, where to buy it from, and at what price. In this randomized control trial (RCT) , we will introduce discount vouchers at five different levels for shrimp farmers as the key intervention. These vouchers will be distributed among randomly selected subsets of shrimp farmers in July 2024 so that they can purchase the specific pathogen-free (SPF) Bagda post-larvae (PL) to produce shrimp on their own ponds. The vouchers will remain redeemable until September 30, 2024.

2024-07-06

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)

Our enumerator will visit each farmer and provide them with the information card. During the same visit, enumerators will conduct a lottery to distribute the vouchers. Each of the five types of vouchers has a unique number on the top--that is, the voucher for treatment group 1 is marked with the number 1, the voucher for treatment group 2 is marked with the number 2., and so on. The control group coupon is marked with 6, which will not provide any discount. However, the control group coupon mentions that the farmer can still buy the SPF-PL at the market price.

Each farmer will have an equal chance to receive one of the 5 discount vouchers that offer a monetary discount or one with no monetary discount. To decide which of these voucher cards he is qualified to receive, the enumerator will put these six tokens in an opaque bag and ask him/her to pick one of them randomly without looking at it. Each of these tokens has a number from 1 to 6. Whichever number the farmer will pick, the enumerator will give him/her the voucher with that number.

Each farmer in the sample will receive a voucher for a range of discounts on one of two types of SPF-PL (Type A: sells at BDT 800 per 1,000 PL; Type B: sells at BDT 1,200 per 1,000 PL). Treatment group 1 will receive a discount of BDT 100 for the type-A SPF-PL, while treatment group 2 will receive a discount of BDT 50 for the same type of SPF-PL. Treatment groups 3, 4, and 5 will receive a discount of BDT 500, BDT 400 and BDT 200, respectively, for the type-B SPF-PL. The control group will be those who will not receive any discount voucher (group 6).

A farmer will be allowed to redeem their voucher for a MAXIMUM of 16,000 units of SPF-PL following the suggestions provided by the DoF for an acre of pond. Each voucher can be redeemed only once. If the treated farmers want to buy more than 16 thousand SPF-PL, they will have to buy the rest of the SPF-PL beyond 16 thousand at the regular market price.

If the treated farmers want to buy more than 16 thousand SPF-PL, they will have to buy the rest of the SPF-PL beyond 16 thousand at the regular market price. The rest will be a control group. The exact monetary values of the discount vouchers are determined based on extensive field visits, price data from the previous rounds of surveys, and discussions with stakeholders. While other factors may work behind the decision to adopt, our randomized intervention will allow us to investigate the causal connection between the redemption of discount vouchers and the decision to adopt SPF-PL.

Desh Bangla Hatcheries, a leading producer and supplier of SPF-PL, will sell and deliver the SPF-PL to shrimp farmers using the discount amount written on the discount voucher. IFPRI, through the implementation partner Evaluation and Consulting Services Ltd. (ECONS), will bear the responsibility of paying the discounted amount to Desh Bangla at the agreed-upon interval.

Not available

Individual level lottery during visits

Randomization is done at the level of individual 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.

No

Not applicable. The randomization is done at the individual level

1222 shrimp farmers

Based on the lottery at the individual level conducted by the enumerators during the visit, we expect to have approximately 200 shrimp farmers in each treatment arm for treatment groups 1 to 5 and the control group)