Table 1.
Description of variables
| Variables | Variable description | unit | |
|---|---|---|---|
| yi | value of crop output | Birr | |
| x1 | area of cultivated land | hectare | |
| x2 | value of owned farm implements | Birr | |
| x3 | number of oxen days used | oxen-days | |
| x4 | labor used in crop production | labour-days | |
| x5 | fertilizer | kg | |
| x6 | seed used | kg | |
| Vi | a disturbance term with normal properties | ||
| Ui | farm specific error term | ||
| Z1 | age of the respondent in years | number | |
| Z2 | education, i.e. literacy status of the farmer | dummy | 1 = literate, 0 = otherwise |
| Z3 | sex of the house hold head | dummy | 1 = male, 0 = female |
| Z4 | membership to association | dummy | 1 = member 0 otherwise |
| Z5 | off farm income | dummy | 1 = have non-farm income 0 = otherwise |
| Z6 | access to irrigation | dummy | 1 = irrigated, 0 = otherwise |
| Z7 | credit | dummy | 1 = loan taken, 0 = otherwise |
| Z8 | number of crop type2 | number | |
| Z9 | distance to woreda market | km |
Table 2.
Generalized Likelihood ratio test of hypotheses for parameters of stochastic production frontier and technical inefficiency factors
| Null hypotheses | LR | Critical value | Decision |
|---|---|---|---|
| Absence of inefficiency H0: δi = 0 = γ | 33.5 | 29.1a | reject |
| Production function is Cobb-Douglas H0: βji = 0 | 29.4 | 32.7b | do not reject |
a This value is obtained from Table 1 in Kodde and Palm (1986) , which gives critical values for tests of null hypothesis involving values of the boundary of the parameter space.
Table 3.
Estimates of the conventional inputs
Table 4.
Estimates of the inefficiency parameters
| Parameter | Coefficient | Standard-error | t-ratio |
|---|---|---|---|
| Constant | 1.99** | 0.98 | 2.02 |
| Head's sex | 0.63 | 0.69 | 0.90 |
| Head's age | −0.10** | 0.053 | −1.96 |
| Off farm income dummy | 0.75 | 0.44 | 1.52 |
| Extension participation | −0.10 | 0.77 | −0.13 |
| Irrigation | −5.54** | 3.44 | −1.69 |
| credit | 0.14 | 0.38 | 0.38 |
| Distance to market | 0.48 | 1.33 | 1.83 |
| Number of crop type | −0.89** | 0.50 | −1.75 |
| Sigma-squared | 2.72 | 1.02 | 2.64 |
| Gamma | 0.82 | 0.083 | 9.83 |
| log likelihood function | −329.5 | ||
| LR test of the one-sided error | 33.5 |