Does contract farming affect technical efficiency? Evidence from soybean farmers in Northern Ghana

Selorm, Ayeduvor; Sarpong, D. B. S.; Egyir, Irene S.; Mensah Bonsu, Akwasi; An, Henry

doi:10.1186/s40100-022-00240-9

Agricultural and Food Economics

Table 4 SPF estimates using matched sample

From: Does contract farming affect technical efficiency? Evidence from soybean farmers in Northern Ghana

Variables	Conventional SPF						Sample selection correction SPF
	Pooled		Contract farmers		Non-participants		Contract farmers		Non-participants
	Coeff.	Z-stat	Coeff.	Z-stat	Coeff.	Z-stat	Coeff.	Z-stat	Coeff.	Z-stat
Constant	0.029	0.37	− 0.118	− 0.94	0.126	1.23	− 0.336**	− 2.22	0.011	0.1
Labor	0.275***	4.46	0.251**	2.49	0.299***	3.79	0.252**	2.11	0.280**	2.45
Fertilizer	0.039***	3.08	0.052**	2.47	0.028*	1.8	0.049*	1.8	0.024	1.3
Seed	0.571***	3.7	0.522**	2.04	0.637***	3.25	0.579**	2.37	0.647**	2.4
Herbicide	− 0.136***	− 3.25	− 0.198***	− 2.67	− 0.131**	− 2.56	− 0.210***	− 2.59	− 0.125**	− 2.04
Labor²	0.206***	3.76	0.273***	2.75	0.181***	2.69	0.237**	1.99	0.207***	2.64
Fertilizer²	0.001	1.62	0.001	1.1	0.001	1.1	0.002	1.46	0.0003	0.32
Herbicide²	− 0.025***	− 2.69	− 0.021	− 1.13	− 0.025**	− 2.38	− 0.017	− 0.9	− 0.035***	− 3.5
Seed²	0.019	0.36	0.160	1.48	− 0.017	− 0.26	0.169	1.39	− 0.035	− 0.47
Labor × Fertilizer	− 0.013*	− 1.71	− 0.017	− 1.38	− 0.010	− 1.02	− 0.012	− 0.91	− 0.012	− 1.11
Labor × Herbicide	− 0.023	− 1.18	− 0.050	− 1.49	− 0.005	− 0.23	− 0.059	− 1.63	− 0.014	− 0.52
Labor × Seed	− 0.209***	− 3.13	− 0.166*	− 1.68	− 0.227**	− 2.37	− 0.120	− 0.79	− 0.271**	− 2.04
Fertilizer × Herbicide	− 0.001	− 0.2	− 0.0003	− 0.07	− 0.001	− 0.36	− 0.0001	− 0.02	0.002	0.5
Fertilizer × Seed	− 0.005	− 0.85	− 0.011	− 1.15	− 0.002	− 0.24	− 0.015	− 1.06	− 0.003	− 0.3
Herbicide × Seed	0.042	0.8	− 0.047	− 0.43	0.054	0.89	− 0.077	− 0.7	0.104	1.62
Power Tillage	0.098**	2.36	0.183***	3.03	0.033	0.57	0.140**	2.08	0.015**	0.24
Bawku West District	0.154**	2.47	0.175*	1.77	0.150*	1.86	0.139	1.28	0.147	1.5
Nanumba South District	0.209***	3.16	0.217**	2.09	0.185**	2.15	0.167	1.53	0.144	1.33
Karaga District	0.126*	1.84	0.048	0.46	0.173*	1.93	− 0.024	− 0.21	0.122	1.18
Variance	0.500***	5.17	0.487***	4.65	0.510***	9.06
Lambda	0.988***	8.45	0.816***	6.42	1.263***	7.28
Sigma (u)							0.488***	6.09	0.509***	8.57
Sigma (v)							0.487***	10.12	0.384***	11.71
Rho(ρ)							0.959***	10.92	0.967***	15.68
Log-likelihood ratio	− 273.911		− 122.187		− 143.025		− 299.045		− 298.054
Returns to scale (RTS)	0.743		0.748		0.782		0.778		0.770
No. of observations	511		221		290		221		290

***, **, and * denote significance at 1%, 5%, and 10% levels, respectively

Back to article page