Short-Term Impacts of Oxen on Agricultural Production and Labor Supply in Côte d’Ivoire

Last registered on July 21, 2022


Trial Information

General Information

Short-Term Impacts of Oxen on Agricultural Production and Labor Supply in Côte d’Ivoire
Initial registration date
July 13, 2022

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
July 21, 2022, 12:36 PM EDT

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



Primary Investigator

Banque Mondiale

Other Primary Investigator(s)

PI Affiliation
World Bank
PI Affiliation
World Bank

Additional Trial Information

Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Most rural households in lower-income countries rely on farming as their primary source of income, and on labor as the primary input to agricultural production. Mechanization, particularly in the form of animal traction, has the potential to raise agricultural incomes and facilitate the structural transformation of developing country economies. Although previous research has identified the conditions which favor the adoption of animal traction, observational studies on its potential benefits yield nuanced results and there is a dearth of rigorous evidence on impacts. In addition to knowledge gaps around how mechanization influences the economies of agricultural households, we also know little about whether (and why) technology adoption has differential impacts within the household.
In a two-year randomized phase-in trial conducted with 2,546 cotton farmers in four northern regions of rural Cote d’Ivoire, we test the impacts of a matching grant that covered 50 percent of the cost and the delivery of a pair of oxen. In economic terms, this is a large treatment: Previous studies have found that an ox is worth about 5 to 8 men, and that traction oxen are at least twice as powerful as smaller bovines: 400-500 watts of power versus less than 200 watts for small bovines (Smil, 2004; Starkey and Faye, 1990).
The sampling frame is composed of members of participating cotton societies. Members are eligible if they fulfill certain objective criteria (such as being married, having been a member of a cotton society for at least 3 years, and belonging to a single cotton society) and more subjective criteria determined by cotton society staff (being credit-worthy, trust-worthy and able to increase their cotton farmland by at least 4 hectares). We use a randomized phase-in approach for our experiment: from the initial sample frame of 2,546 eligible farmers, we randomly assign 1,273 producers to receive an oxen matching grant in an initial batch (treatment group) and 1,273 to receive the offer starting in 1.5 years later (control group).
Due to budget and timing constraints, we do not have baseline data in this experiment. We use non-varying demographic variables, as well as pre-program administrative data for a sub-sample of around half of the cotton producers, to test for balance. The main survey respondent is the household head, with specific questions on the receipt and use of oxen addressed to the producer in instances where the two diverge. We additionally randomly select and survey one girl and one boy in each household and administer numeracy and literacy assessments.
External Link(s)

Registration Citation

Brudevold-Newman, Andrew, Aletheia Donald and Léa Rouanet. 2022. "Short-Term Impacts of Oxen on Agricultural Production and Labor Supply in Côte d’Ivoire." AEA RCT Registry. July 21.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Agricultural outcomes: production, value of harvest sold, land holdings, land cultivated - overall and by crop
Household income: total household income, total farm income, total non-farm income
Labor: hired labor on plots, household labor (by household members) on plots and off-farm
Non-labor inputs: use of oxen (intensive and extensive), use of fertilizer and phytosanitary products, value of non-labor inputs used on household plots
Time use for all household members
Education (school attendance, school drop-out, assessment scores) of children
Health of all household members (sickness)
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We use a randomized phase-in approach for our experiment: from an initial sample frame of 2,546 eligible farmers, we randomly assigned 1,273 producers to receive the oxen matching grant offer in an initial batch (treatment group) and 1,273 to receive the offer starting in 1.5 years later (control group).
Experimental Design Details
Randomization Method
Computer based
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Sample size: planned number of observations
2,546 cotton farmers
Sample size (or number of clusters) by treatment arms
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number


Post Trial Information

Study Withdrawal

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Is the intervention completed?
Intervention Completion Date
June 30, 2018, 12:00 +00:00
Data Collection Complete
Data Collection Completion Date
December 31, 2018, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
Final Sample Size (or Number of Clusters) by Treatment Arms
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials