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The Official Journal of the Pan-Pacific Association of Input-Output Studies (PAPAIOS)

Table 4 OLS and ML estimate of production frontier for black cumin producers

From: Estimation of technical efficiency of black cumin (Nigella sativa L.) farming in northwest Ethiopia: a stochastic frontier approach

Variables Parameters Ordinary least square estimates Maximum likelihood estimates
Coefficient Std. err Coefficient Std. err
Constant \(\beta_{0}\) 0.547* 0.324 0.683** 0.345
Lnseed \(\beta_{1}\) 0.190** 0.080 0.332*** 0.097
LnNPS \(\beta_{2}\) 0.032 0.026 − 0.043 0.031
Lnland \(\beta_{3}\) 0.240** 0.097 0.227** 0.103
LnChemical \(\beta_{4}\) 0.251*** 0.047 0.185*** 0.049
LnOxen \(\beta_{5}\) 0.049 0.114 0.052 0.112
LnLabor \(\beta_{6}\) 0.159* 0.085 0.202** 0.080
Sigma-squared \(\left( {\sigma^{2} } \right)\)     0.211*** 0.036
Gamma \(\left( \gamma \right)\)     0.849*** 0.076
Return to scale     0.946  
Log likelihood function   − 127.582   − 91.247  
Total sample size   188   188  
  1. ***, ** and * are statistically significant at 1%, 5% and 10%, respectively