استعمال نماذج الإبطاء الزمني في تقدير أثر المساحة و أثر الأسعار على إنتاج الرز في العراق : دراسة قياسية باستعمال نموذجي Adhoc, Koyck

الملخص EN

The research aimed to study the impact of area and the impact of prices on rice production in Iraq by using Adhoc model for exogenous lagged variables with OLS method , and Koyck model for indogenous variables by using OLS and IV methods depending on time series for the period 1980 -2008 .

The results showed that the effect of area over the impact of prices in rice production according to Adhoc model and it explains 64%of the production change , it also explains 71%of the change in production when used in Koyck model , and the prices explains 59% of the production changes in same model .

There is considerable variation in the indicators of lagged variables between the impact area and the impact of prices in production increase according to Koyck model and OLS method for seak of the area ten times for short and long run impact .

There are very effective for the weights of lagged variables to conversion area and prices to final product in the first three years by 90% and 95% for each respectively.

the study concluded the need to use lagged variables in the economic analysis of The importance and contribution in making the right decision by producers in the allocation of economics resources .