Does Off-Farm Work Improve Farm Income? Empirical Evidence from Tolon District in Northern Ghana

Table 4

Results of the Heckman selection model of off-farm work and farm income.

Independent variables	Probit model		Outcome equation
	Coefficient	Std. error	Coefficient	Std. error
Sex	−0.523	0.241	437.2	552.0
Age	0.290	0.096	−814.0	223.9
Age squared	−0.004	0.001	12.26	2.992
Education	0.054	0.018	−18.41	37.86
Farm size	0.590	0.127	849.6	150.3
Access to credit	−0.116	0.236	1281	541.3
Number of dependents	−0.121	0.050
Constant	−5.610	1.901	14202	4283
Inverse Mill’s ratio (λ)			−81.68	0.095
Rho	−0.881	0.079
Sigma	2342.7	303.5
Lambda	−2064.7	423.4
Selected observations	64
Unselected observations	86
Wald chi^2 (6)	187
Prob > chi^2	0.00

LR test of independent equations (rho = 0): chi²(1) = 8.94, prob > chi² = 0.003. Statistical significance at 10% level. Statistical significance at 5% level. Statistical significance at 1% level. (6) and (1) indicate the degrees of freedom for the chi-squared estimation.