Download StudyGeneral

Study Overview

Evaluation of AgResults Nigeria Aflasafe Pilot
Study is 3ie funded:
Study ID:
Initial Registration Date:
Last Update Date:
Study Status:

This study uses a combination of qualitative analysis and a randomized control trial (RCT) to evaluate the impact of the Nigeria Aflasafe pilot (one of several AgResults pilots) on smallholder impacts and technology uptake. The ultimate objective of the evaluation is to assess whether pull mechanisms serve as an effective way to incentivize technology adoption within the context of the pilot. The Nigeria Aflasafe Pilot focuses on incentivizing maize aggregators’ procurement of maize treated with Aflasafe, a new biocontrol technology to reduce the prevalence of aflatoxins. Aflatoxins are toxic to humans and are produced by naturally occurring fungi in soil, contaminating a variety of food commodities. Using native Aspergillus strains –which are incapable of producing aflatoxin– to crowd out aflatoxin-producing strains, Aflasafe prevents aflatoxin formation in the field and continues to protect grains from contamination through transport and storage. Extensive field tests of Aflasafe in Nigeria have shown an average of 80% reduction in aflatoxin levels in treated crops, and up to 99% reduction in some cases.

Registration Citation:

Bell, S., and Narayan, T., 2015. Evaluation of AgResults Nigeria Aflasafe Pilot. Registry for International Development for Impact Evaluations (RIDIE). Available at: 10.23846/ridie061

Agriculture and Rural Development
Economic Policy
Health, Nutrition, and Population
Private Sector Development
Additional Keywords:
Aflatoxin, Randomized control trial, RCT, Aflasafe, Nigeria, maize, pull mechanism, impact evaluation, qualitative evaluation, technology adoption
Secondary ID Number(s):

Principal Investigator(s)

Name of First PI:
Stephen Bell
Abt Associates
Name of Second PI:
Tulika Narayan
Abt Associates

Study Sponsor

Department for International Development (DFID)
Study Sponsor Location:
United Kingdom

Research Partner

Name of Partner Institution:
Denise Mainville Consulting
Type of Organization:
Private firm
United States

Intervention Overview


The pilot uses a “pull” mechanism—financial incentives to private sector actors in the value chain—to stimulate demand for Aflasafe-treated maize and its production by smallholders. Specifically, the pilot provides aggregators incentives in the form of price premiums (USD $18.44 per metric ton) for procuring maize treated with Aflasafe. There are no restrictions on the use of those incentives; the aggregator may or may not offer price premiums or other incentives to smallholders in order to procure the smallholders’ maize treated with Aflasafe. Although there are no requirements to do so, the pilot encourages the aggregators to use contract farming arrangements for encouraging the application of Aflasafe in maize fields by smallholders. The premiums are based on presence of Aflasafe rather than absence of aflatoxins because climatic conditions determine the presence of aflatoxins, and it may be that the maize of a farmer who did not apply Aflasafe (or did not adopt the technology being promoted) can have low levels of aflatoxins.

Theory of Change:
Multiple Treatment Arms Evaluated?

Implementing Agency

Name of Organization:
Type of Organization:
Foreign or Multilateral Aid Agency

Program Funder

Name of Organization:
The World Bank
Type of Organization:
Foreign or Multilateral Aid Agency

Intervention Timing

Intervention or Program Started at time of Registration?
Start Date:
End Date:
Evaluation Method

Evaluation Method Overview

Primary (or First) Evaluation Method:
Randomized control trial
Other (not Listed) Method:
Additional Evaluation Method (If Any):
Other (specify)
Other (not Listed) Method:

Method Details

Details of Evaluation Approach:

A subset of participating aggregators indicated that they were willing to work with the evaluation team to randomly assign the areas (villages) into treatment and comparison groups. These aggregators provide the evaluator with a list of villages where they planned to implement AgResults activities over a set of future years; in total, the aggregators submitted the names of 229 villages. The evaluator then randomized each aggregator’s villages into four cohorts for staggered implementation. Each year, the participating aggregators will add one of these cohorts of villages to their actual implementation activities, thus gradually moving random cohorts of villages from comparison to treatment status. Hence, villages that receive treatment in the first and second years are in the treatment group (Cohorts A and B), and villages that receive treatment in later years serve as the control group (Cohort C). This approach is sometimes referred to as a randomized “step wedge” design. The evaluation will examine the mean differences in smallholder outcomes between the treatment and control group using linear regression models with village level random effects.

Outcomes (Endpoints):

The primary outcomes of interest are smallholder uptake of Aflasafe, smallholder maize revenue, smallholder income, and smallholder consumption of maize treated with Aflasafe. Intermediate outcomes of interest are smallholder knowledge of aflatoxin, smallholder knowledge and proper application of Aflasafe. Goals for the evaluation are not restricted the quantitative analysis of smallholder data from the randomized controlled trial. The analysis of the randomized controlled trial will be complemented by a synthesis qualitative information to assess: private sector engagement in the uptake of Aflasafe, whether or not the impacts of the pilot are scalable and sustainable in the medium to long term, the cost-effectiveness of the pilot, and lessons learnt about best practices in the design and implementation of agricultural pull mechanisms.

Unit of Analysis:

Primary hypothesis: Smallholders smallholders (identified at baseline by the aggregators) who live in the Year 2 cohort villages (treatment group) have the same mean levels of the following measures as smallholders (identified at baseline by the aggregators) who live in villages randomly assigned to the control condition (Year 4 cohort) after 1-2 years of treatment: uptake of Aflasafe, maize revenue, income, consumption of maize treated with Aflasafe, knowledge of aflatoxin, smallholder knowledge and proper application of Aflasafe. Secondary hypotheses will also examine the Year 1 cohort data (for which baseline data are not available, and thus the contrasts do not hold as much statistical power). We do not analyze the Year 3 cohort because of concern regarding treatment “contamination” in this cohort.

Unit of Intervention or Assignment:
Number of Clusters in Sample:
Number of Individuals in Sample:
Size of Treatment, Control, or Comparison Subsamples:
The primary analysis will include 42 villages in the treatment group (Yr 2 Cohort) and 40 villages in the control group (Yr 4 cohort), with an expected sample of 8 farmers per village.

Supplementary Files

Analysis Plan:
AgResults Evaluation Design_Nigeria Aflasafe_12-30-14_ANON.docx
Other Documents:

Outcomes Data

The data used for the impact assessment will be collected using one baseline and one or two (as budget and implementers' adherence to random assignment allows) endline household surveys. The data for the qualitative assessments will be collected using baseline and endline interviews and focus groups with various entities involved in various aspects of the value chain.
Data Already Collected?
Data Previously Used?
Data Access:
Data Obtained by the Study Researchers?
Data Approval Process:
Approval Status:

Treatment Assignment Data

Participation or Assignment Information:
Data Obtained by the Study Researchers?
Data Previously Used?
Data Access:
Data Obtained by the Study Researchers?
Data Approval Process:
Approval Status:

Data Analysis

Data Analysis Status:

Study Materials

Upload Study Materials:

Registration Category

Registration Category:
Prospective, Category 1: Data for measuring impacts have not been collected

Completion Overview

Intervention Completion Date:
Data Collection Completion Date:
Unit of Analysis:
Clusters in Final Sample:
Total Observations in Final Sample:
Size of Treatment, Control, or Comparison Subsamples:


Preliminary Report:
Preliminary Report URL:
Summary of Findings:
Paper Summary:
Paper Citation:

Data Availability

Data Availability (Primary Data):
Date of Data Availability:
Data URL or Contact:
Access procedure:

Other Materials

Survey Instrument Links or Contact:
Program Files:
Program Files Links or Contact:
External Link:
External Link Description:
Description of Changes:

Study Stopped