Spillovers as a Driver to Reduce Ex-post Inequality Generated by Randomized Experiments:
Evidence from an Agricultural Training Intervention


Randomized experiments ensure equal opportunities but could generate unequal outcomes by treatment status, which is socially costly. This study demonstrates a sequential intervention to conduct impact evaluation and subsequently to mitigate “experiment-driven” inequality. Specifically, control farmers were initially restricted from exchanging information with treated farmers, who received rice management training, to satisfy the stable unit treatment value assumption. We then encouraged information exchange between farmers one year after the training. We found positive training effects, but performance gaps created by our randomized assignment disappeared over time because of information spillovers and, hence, eventually control farmers also benefitted from our experiment.

Report No.: HIAS-E-69
Author(s): Kazushi Takahashi(a)
Yukichi Mano(b)
Keijiro Otsuka(c)
Affiliation: (a) Sophia University, Faculty of Economics, Tokyo 102-8554, Japan
(b) Hitotsubashi University, Graduate School of Economics, Tokyo 186-8601, Japan
(c) Kobe University, Graduate School of Economics, Hyogo 657-8501, Japan
Issued Date: May 2018
Keywords: Inequality, Program evaluation, Randomised experiment, Spillover
JEL: O12, O13, O31, Q12