evaluating eco-climatict variables on wheat yield using panel data model

abstract in order to evaluation the effects of price policies (wheat guarantee price in each period and its price lag), environmental (planted area) and climatic (min and max average temperature, total annual precipitation, cold-day degree and hot-day degree) factors, we considered wheat yield in razavi-khorasan province (9 cities) for a 13-year statistical period (1371-72 to 1383-84). in this study, we used panel data model to evaluate and analyze the effects of cross-sectional and time- series variations of explicative variables on wheat yield. the results show that min average temperature, price of previous period and spring precipitation variables have significant and positive effects and cold-degree day variable has a significant and negative effect on wheat yield. although the significance of the estimations in 95% confidence interval is high, one-way error component results points out that wheat yield has a low-elasticity against the explicative variables, such that, its elasticity to min average temperature, price of previous period and spring precipitation and cold-degree day is respectively: 0.26, 0.13, 0.15 and -0.28 . therefore, the estimated results reveals that wheat yield is low-elastic in relation to explicative variables, and amongst them wheat yield is more-elastic to cold-degree day variable. so, one-way error component model is suitable for wheat yield estimation.