RELATIONSHIPS AMONG LABOR, BULLOCK, AND TRACTOR INPUTS IN PAKISTAN AGRICULTURE

The Purpose of this study is to examine relationships among different inputs on tractorized and non-tractorized plots in the North West Frontier Province of Pakistan. The analysis is based on survey data for 1987-88 covering two seasons. A duality approach with a translog cost function is used to estimate cost and input shares. The estimated Allen elasticities of substitution, after correcting for sample selectivity bias, indicate that tractors are a substitute for human and animal labor. All the assumptions of the duality approach are fulfilled by the estimation procedure and the restrictions of theory are not rejected by the data.