استفاده از آب آبیاری و کارایی فنی: حسابداری برای ناهمگونی تکنولوژیکی و محیطی در کشاورزی ایالات متحده با استفاده از پارامترهای تصادفی

Decision-making units (DMUs) face considerable variations in their production possibilities as well as the characteristics of the production environments under which they operate. Consequently, DMUs are likely to experience substantial differences in productivity and efficiency levels. In contrast, the received literature assumes that DMUs share similar technological possibilities and only differ with respect to their level of inefficiency. This study develops an analytical framework using random parameters, which accommodates heterogeneity in production possibilities and in characteristics of the production environment. We use this framework to analyze variations in the output elasticity of irrigation across DMUs, and how these differences influence: 1) irrigation water use efficiency (IWUE), using a non-radial input-oriented approach that isolates and measures the efficient use of the irrigation input; 2) technical efficiency, which radially measures the efficient utilization of all inputs; and 3) shadow prices of irrigation withdrawals. We find that IWUE and technical efficiency averaged 72.6% and 83.6%, respectively, and shadow prices averaged $77.5 per million gallons of irrigation water, albeit with significant regional variations.