Paying Smallholder Farmers to Increase Carbon Sequestration by Changing Agricultural Practices: Evidence from Odisha

In the intervention, farmers will receive a discount coupon for rotavator services. Some will receive a set discount, and some will receive a variable discount based on how many of their neighbors sign up for the rotavator services.

2026-01-01

2026-03-31

The primary outcomes are
1) to measure adoption responses to individual and group-targeted rotavator subsidies, assessing whether group-based offers change uptake relative to individual offers and
2) to evaluate whether adding a cluster-level SOC-linked bonus payment increases adoption, beyond the group-coordination effect generated purely by simultaneous offers.

Secondary outcomes are
1) to test the operational feasibility and analytical performance of grid-based SOC sampling across all arms,
2) to study the evolution of adoption behavior across two consecutive agricultural seasons, examining both initial uptake and short-run persistence,
3) to document and quantify spillovers within and across clusters, including machine-use diffusion, peer learning, and behavioral contagion, and
4) to contribute evidence relevant for carbon-credit program design, particularly regarding the comparative cost-effectiveness of individual vs. cluster-based subsidy models.

Groups of 10 spatially contiguous farmers will be randomly offered different financial incentives to adopt the use of a rotavator. Some will be offered incentives at an individual level and others will be offered incentives at a group level. There will be three treatment arms:
1) individual coupon for rotavator use,
2) group coupon for rotavator use and no additional payment, and
3) group coupon for rotavator use plus a group-based SOC-linked bonus at the end of the study.

Not available

Randomization done in office by a computer

Groupings of 10 spatially contiguous farms

Yes

250 clusters of 10 farms each

2,500 farms

Approximately 714 farms assigned to each of the three treatment arms and 358 farms assigned to the control group.

For a minimum detectable effect of 0.259 tC/ha and a standard deviation of 1.64 tC/ha, we need at least 1,666 farmers for 80% power at 5% significance. To allow for attrition, we will enroll 2500 farmers.