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This study shows the application and the importance of the Tobit and the Two - stage Heckman econon1etric models in specifying factors affecting sugar beet production in Khorasan, and the uses of these models in differentiating factors influencing farmers' decision to cultivate this crop from those determining the area under cultivation. In addition, the study indicates the bias of estimated parameters of the OLS-based models resulting from excluding the sample information on potential farmers as well as not differentiating the two groups of the influential factors. The results of the study reveal that the factors influencing farmers' decision to cultivate sugar beet are not the same as those affecting the area under cultivation. Therefore, using econometric models such as Heckman model, which takes into account these differences, is recommended. In addition, the results lead to the conclusion that the estimated parameters of OLS - based model are biased. Thus, using these parameters may result in inappropriate policy recommendations.