Climate variability, agricultural technologies adoption, and productivity in rural Nigeria: a plot-level analysis

Table 7 Impact of SAPs on plot-level productivity (log value of harvest per hectare)

Variable	OLS		IVREG2H
Variable	Coefficient	Std error	Coefficient	Std error
Improved seeds	0.032	0.055	0.104	0.146
Inorganic fertilizer	0.324***	0.034	0.305*	0.179
Organic fertilizer	0.019	0.040	− 0.427***	0.140
Legume intercropping	− 0.092**	0.038	0.034	0.097
Growing season rainfall (mm)	0.000*	0.000	0.000	0.000
Start of wettest dekad in 2018	− 0.017**	0.008	− 0.019*	0.010
Household size	0.027	0.029	0.047	0.034
Dependency ratio	0.043***	0.014	0.042***	0.016
Gender	− 0.001	0.001	− 0.001	0.001
Age	0.156***	0.051	0.161***	0.056
Education	− 0.004	0.004	− 0.007*	0.005
Off farm	− 0.044	0.033	− 0.031	0.041
Wage work	− 0.104**	0.053	− 0.109*	0.063
Extension	0.093**	0.042	0.105**	0.048
Own plot	0.032	0.039	0.055	0.043
Erosion control	− 0.132	0.139	− 0.215	0.139
Steep slope	− 0.033	0.038	− 0.039	0.041
Irrigation	0.244***	0.094	0.268***	0.099
Distance to market	0.000	0.000	− 0.001	0.000
Nutrient constraint	− 0.148***	0.025	− 0.134***	0.028
NDVI in 2018	1.805***	0.406	1.635***	0.561
Distance to household	0.002	0.004	0.002	0.004
Wealth Index	0.078***	0.030	0.093***	0.036
Agric capital index	0.019	0.015	0.030	0.019
Tropical livestock unit	− 0.010***	0.004	− 0.008	0.005
North Central	0.011	0.139	− 0.028	0.162
North East	− 0.398***	0.140	− 0.409**	0.170
North West	0.040	0.144	0.156	0.195
South East	0.278*	0.156	0.268	0.183
South West	0.613***	0.164	0.545***	0.194
Constant	11.856***	0.283	11.966***	0.374
Sample size	5,616		5616
R²	0.070		0.050
Wald	15.8***		10.54***
Underidentification test			136.19**
Weakidentification test			2.673***
Overidentification test (Hansen J statistic)			56.60

ISSN: 2048-7010