Working Paper: NBER ID: w18778
Authors: Lori A. Beaman; Dean Karlan; Bram Thuysbaert; Christopher R. Udry
Abstract: In an experiment providing fertilizer grants to women rice farmers in Mali, we found that women who received fertilizer increased both the quantity of fertilizer they used on their plots and complementary inputs such as herbicides and hired labor. This highlights that farmers respond to an increase in availability of one input by re-optimizing other inputs, making it challenging to isolate the returns to any one input. We also found that while the increase in inputs led to a significantly higher level of output, we find no evidence that profits increased. Our results suggest that fertilizer's impact on profits is small compared to other sources of variation. This may make it difficult for farmers to observe the impact of fertilizer on their plots, and accordingly this affects their ability to learn about the returns to fertilizer and could affect their decision to adopt even in the absence of credit constraints.
Keywords: fertilizer; rice farmers; Mali; agricultural productivity
JEL Codes: O12; O13; Q12
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| Impact of fertilizers on profits is small compared to other sources of variation (Q12) | Difficulty in observing returns on fertilizer use (Q16) |
| Provision of fertilizer (Q16) | Increased fertilizer usage (Q16) |
| Provision of fertilizer (Q16) | Increased complementary inputs (D10) |
| Increased input usage (C67) | Higher output levels (E23) |
| Increased input usage (C67) | Increased profits (D33) |
| Provision of fertilizer (Q16) | Increased profits (D33) |