آزمون سازگاري جمع‌سازي جغرافيايي بنگاهها در بخش كشاورزي ايران‌

Testing Geographical Aggregation Consistency Across Agencies in Agriculture Sector of Iran

Theory of the firm investigates the behavior of individual producers; however, in many cases researchers inevitably use aggregated data in empirical studies since disaggregated data are not available or are costly to collect. In addition, working with aggregated data in modeling producerʹs behavior is easier and more desirable, particularly in policy analysis. Despite the attractive features of aggregated data, using these data in aggregate econometrics models results in biased parameter estimates and depicts unrealistically producersʹ behavior and consequently lead to unreliable inferences. In this study, we examine the aggregation consistency condition for price and quantity aggregation across 6 large paddy producer provinces and also 24 wheat producer provinces, resorting to the Generalized Composite Commodity Theorem (GCCT). Results indicate that group quantity and price indices are respectively independent from relative quantities and prices for wheat and paddy across all provinces. Consequently, consistent geographic aggregation was supported for each price and quantity data at the country level.