An experimental approach to farmer valuation of African rice genetic resources

Last registered on October 17, 2020


Trial Information

General Information

An experimental approach to farmer valuation of African rice genetic resources
Initial registration date
October 05, 2020

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
October 06, 2020, 7:28 AM EDT

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

Last updated
October 17, 2020, 4:35 AM EDT

Last updated is the most recent time when changes to the trial's registration were published.


Primary Investigator


Other Primary Investigator(s)

PI Affiliation

Additional Trial Information

In development
Start date
End date
Secondary IDs
This project aims to investigate the value that rice farmers in Côte d’Ivoire place on both African rice landraces maintained by the AfricaRice genebank as well as advanced rice varieties developed through AfricaRice’s breeding programs such as the inter-specific hybrid ARICA varieties and the aromatic Oryza sativa variety ORYLUX. This will take place through a field experiment including the implementation of a payment for agrobiodiversity conservation services (Drucker and Ramirez 2020) programme for landraces and the assignment of seed of advanced rice varieties based on the willingness-to-pay (WTP) of surveyed farmers. Methodologically, we will combine a typical randomized controlled trial approach with a simplified version of the open selective trials methodology proposed by Chassang et al. (2012).

AfricaRice manages one of the largest collections of drought-tolerant African rice (Oryza glaberrima) in the world, as well as traditional African landraces of Oryza sativa (Asian rice), which is thought to have been introduced to West Africa in the 1500s. Domesticated in West Africa about 3,000 years ago and indigenous to the continent, the cultivation of Oryza glaberrima has declined and been replaced in farmers’ fields in many cases by the higher-yielding Asian rice (Oryza sativa). However, its genetic resources are of interest due to a number of valuable traits such as tolerance to drought, soil acidity, and iron and aluminum toxicity in the genepool, as well as other qualitative traits such as taste, aroma, cooking qualities, and others.

While much research has focused on the impact of the interspecific NERICA varieties bred by AfricaRice (e.g. Kijima et al. 2008), less work has investigated the value of the newer generation of ARICA (and ORYLUX) varieties or attempted to investigate the value farmers place on African rice landraces and farmers' varieties of both Oryza glaberrima and Oryza sativa.

The significance of this research is thus its combined investigation of how farmers value both newer advanced rice varieties bred through AfricaRice’s programmes as well as rice landrace varieties conserved by the AfricaRice genebank (including both O. sativa and O. glaberrima landraces). In addition, the study’s use of an extended randomized controlled trial / open selective trials methodology through a field experiment will be used to investigate how farmer heterogeneity impacts the valuation of rice genetic diversity (both traditional and improved) in the West African context.
External Link(s)

Registration Citation

Tyack, Nicholas and Aminou Arouna. 2020. "An experimental approach to farmer valuation of African rice genetic resources." AEA RCT Registry. October 17.
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Experimental Details


The intervention consists of two treatment arms.

The first treatment arm is the assignment of farmers to cultivate 2 kgs of advanced rice seed released by the Africa-wide Rice Breeding Task Force, including both ARICA varieties (Advanced Rice Varieties for Africa) and ORYLUX, an aromatic variety. However, these varieties are still not widely adopted in Côte d'Ivoire. The goal of this treatment arm is to determine whether or not farmers would prefer these varieties over what they are currently growing if the frictions to diffusion were relaxed by bringing seed directly to the farmer.

The second treatment arm is the assignment of farmers to cultivate 70g of farmer landrace varieties of rice (both Oryza sativa and Oryza glaberrima) from the AfricaRice genebank, the Rice Biodiversity Center for Africa). The objective of this treatment arm is to determine whether farmers would be willing-to-pay for additional seed of these farmer varieties which may possess valuable traits including drought tolerance and good taste.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
The first key outcome variable is willingness-to-pay for additional landrace seed at the end-line survey planned for February 2021.

The second key outcome variable is the change in willingness-to-pay for an additional 2 kg of advanced rice seed from the baseline survey in October 2020 and the end-line survey in February 2021.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
This study’s approach to investigating farmer valuation of African rice varieties (both landraces and advanced varieties) is a combination of the more general randomized controlled trial (RCT) approach with a simplified version of the “open selective trials” methodology of Chassang et al. (2012). The field experiment will involve a modified willingness-to-accept (WTA) auction for the cultivation of a small basket of two African rice landraces from the AfricaRice genebank coupled with a WTP survey of farmers for two kilograms of seed of Advanced Rice Varieties for Africa (ARICA), the newest generation of high-performing rice varieties developed by the Africa-wide Rice Breeding Task Force (along with ORYLUX, another aromatic improved rice variety bred at AfricaRice).

The open selective trials approach is designed for situations where outcomes are influenced substantially by unobserved individual beliefs and efforts (as is the case for technology adoption in agriculture, particularly in the smallholder context). In the context of this experiment, the use of open selective trials will allow us to distinguish between the treatment effect of farmers randomly assigned to cultivate advanced varieties and those who are assigned to do so based upon their high willingness-to-pay to receive 2 kilograms of ARICA/ORYLUX seed (a measure of their expected return of receiving this seed). Similarly, we will be able to distinguish between farmers assigned to grow traditional African rice landraces who have low WTA values for doing so, indicating a greater willingness to experiment with these traditional varieties (and a lower opportunity cost of doing so) from farmers selected at random with higher stated WTA values. The elicitation of these “messages” from farmers regarding WTP and WTA will allow us to identify the distribution of returns conditional on the farmers’ valuations.

Participating farmers in Côte d’Ivoire will be identified using the open selective trial methodology proposed by Chassang et al. (2012). Each farmer will be required to specify how much they would require to be paid to cultivate two African rice landraces on a small plot of land. Similarly, farmers will be asked how much they would be willing to pay to obtain 2 kg total seed, consisting of 1 kg each of either ARICA or ORYLUX varieties. Participating farmers will first be selected randomly into treatment groups (for a portion of the farmers in the village) and will then be selected based on their stated WTA/WTP values (for the other portion of farmers in the village) and provided with small amounts of seed to cultivate over the fall growing season.

At the final survey in February 2021, we will ask farmers whether they would be willing to pay to receive small amounts of landrace seed, and/or 2 kilograms of advanced rice seed. The WTP for landrace seed is the first primary outcome variable, whereas the change in WTP for the 2 kilograms of advanced rice seed between the baseline survey and the endline survey will serve as the second primary outcome variable.
Experimental Design Details
Randomization Method
Some portion of farmers in each village will be randomized by computer in the office, while the rest will be assigned to treatment based upon their stated WTP for advanced rice seed and their stated WTA for cultivating the landrace rice varieties.
Randomization Unit
The unit of randomization is the individual farmer.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Sample size: planned number of observations
Approximately 550 rice farmers across twelve villages.
Sample size (or number of clusters) by treatment arms
Approximately 180 farmers assigned to cultivate 70g of two landrace rice varieties, approximately 180 farmers assigned to cultivate 2 kg of advanced rice varieties, approximately 180 farmers control.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Ethics review process at the Graduate Institute of International and Development Studies
IRB Approval Date
IRB Approval Number


Post Trial Information

Study Withdrawal

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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