فهرست مطالب

اقتصاد و توسعه کشاورزی - سال سی‌ام شماره 4 (زمستان 1395)
  • سال سی‌ام شماره 4 (زمستان 1395)
  • تاریخ انتشار: 1395/12/23
  • تعداد عناوین: 8
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  • علمی - پژوهشی
  • الهام صادقی، رضا مقدسی صفحات 277-284
    پرورش دام سبک یکی از مهم ترین منابع تامین گوشت قرمز می باشد. در کشور ما نرخ رشد سالیانه تولید دام سبک در سال 1393 نسبت به سال 1383، 4/6 کاهش یافته است. از طرف دیگر قیمت نهاده های مورد نیاز برای تولید دام سبک دارای نوساناتی است که بر تصمیم تولیدکنندگان جهت افزایش تولید، تاثیر زیادی دارد. این مطالعه با هدف بررسی اثر نوسانات قیمت نهاده ها بر عرضه ی دام سبک در سطح استانی انجام شده است. جامعه آماری این پژوهش استان های عرضه کننده دام سبک در سطح کشور می باشد که سه استان آذربایجان شرقی، اصفهان و قم از میان آن ها بر اساس میزان سهم در عرضه انتخاب شده است. تحلیل نوسان قیمت ها و ریسک قیمتی بر اساس فرآیند GARCH و واکنش عرضه دام سبک با استفاده از الگوی فضای حالت انجام شده است. نتایج این پژوهش نشان می دهد که در استان های آذربایجان شرقی، اصفهان و قم متغیر قیمت انتظاری دام سبک بر میزان عرضه دام سبک تاثیر مثبت و معنی دار داشته، در حالی که واریانس قیمتی دام سبک بر میزان عرضه آن تاثیر منفی و معنی دار دارد. همچنین، متغیر قیمت انتظاری نهاده های لازم برای عرضه دام سبک و واریانس آن تاثیر منفی و معنی دار بر میزان عرضه آن دارد. نوسانات فصلی مربوط به فصول تابستان، پاییز و زمستان در استان آذربایجان شرقی تاثیر منفی و معنی دار بر عرضه دام سبک داشته است. نوسانات فصلی مربوط به فصول تابستان و پاییز در استان اصفهان تاثیر منفی و معنی دار بر عرضه دام سبک داشته، در حالی که نوسانات فصلی مربوط به زمستان تاثیر مثبت و معنی دار بر عرضه دام سبک داشته است. متغیرهای موهومی مربوط به فصول تابستان و پاییز در استان قم تاثیر منفی و معنی دار و فصل زمستان تاثیر مثبت و معنی دار بر عرضه دام سبک داشته اند. با بررسی نوسانات سیکلی و روند در هر سه استان مشخص می شود که در میزان عرضه دام سبک نوسانات سیکلی و روند معنی دار و مثبت با ضرایب تصادفی در هر سال وجود داشته است. عرضه دام سبک نسبت به تغییرات قیمت نهاده ها و دام سبک کم کشش است و تاثیر ریسک قیمتی دام سبک بزرگتر از ریسک قیمتی نهاده ها می باشد.
    کلیدواژگان: الگوی فضای حالت، دام سبک، عرضه، GARCH
  • باب الله حیاتی، مینا صالح نیا، مرتضی مولائی صفحات 285-296
    یکی از چالش های عمده در زمینه ارزش گذاری، پی بردن به تنوع ترجیحات و حساسیت هایی است که در جوامع مورد بررسی وجود دارد. دریاچه ارومیه به عنوان یک کالای عمومی، نیازمند مداخله مردمی جهت جلوگیری از زوال هر چه بیشتر آن است. از این رو در تحقیق حاضر به مطالعه ترجیحات ساکنین حوضه و بروز ناهمگنی در آن با استفاده از روش آزمون انتخاب اقدام شده است. داده ها و اطلاعات مورد نیاز با تکمیل 450 پرسشنامه از شهروندان 13 شهر و با روش نمونه گیری تصادفی طبقه ای برونزا در سال 1394 به دست آمده و با کاربرد مدل کلاس پنهان چند سطحی مورد تحلیل قرار گرفتند. نتایج مدل به تشخیص سه کلاس در سطح فردی، دو کلاس در سطح گروهی و دو کلاس مقیاس انجامید.طبق نتایج حاصله، اکثر افرادی که در موقعیت جغرافیایی نزدیک تری نسبت به دریاچه ارومیه زندگی می کنند، به کلاس بزرگ واحدی تعلق دارند. این افراد مقادیر بالایی از تمایل به پرداخت را در راستای احیای دریاچه بیان نموده و تغییر آب و هوا و وزش بادهای نمکی (با 580750 ریال در سال به ازای خانوار) نگران کننده ترین مسئله زیست محیطی ناشی از خشک شدن دریاچه برای آنان به شمار می رود. نتایج موید این مطلب است کهنه تنها خصوصیات اقتصادی اجتماعی بلکه خصوصیات ژئوفیزیکی محیط پیرامون اشخاص در شکل گیری نگرش ها، رفتارها، عقاید و در نتیجه انتخاب-های آنها موثر می باشند. همچنین وجود عدم قطعیت در پاسخ های افراد به عنوان سومین عامل تاثیرگذار در مدل سازی ترجیحات تشخیص داده شد. لذا پیشنهاد می شود در مطالعات آتی، بروز ناهمگنی ترجیحات از هر سه منظر فوق مورد توجه قرار گیرد.
    کلیدواژگان: آزمون انتخاب، تمایل به پرداخت، دریاچه ارومیه، مدل کلاس پنهان چند سطحی، ناهمگنی ترجیحات
  • قادر دشتی، خدیجه الفی، محمد قهرمان زاده صفحات 297-307
    مطالعه حاضر با هدف بررسی نحوه اثرگذاری متغیرهای آب و هوایی شامل دما، بارش، سرعت باد و رطوبت بر سهم سطح زیرکشت انواع محصولات سالانه زراعی شامل غلات، حبوبات، سبزیجات، محصولات جالیزی، محصولات علوفه ای و محصولات صنعتی در ایران صورت گرفت. در این راستا با استفاده از اطلاعات زراعی و هواشناسی 336 شهرستان کشور در دوره زمانی 92-1391 اقدام به برآورد مدل لاجیت چندگانه کسری گردید. نتایج مطالعه نشان داد افزایش دما سهم سطح زیرکشت غلات و محصولات جالیزی را افزایش و سهم سطح زیرکشت حبوبات را کاهش می-دهد. لذا با توجه به پیش بینی های صورت گرفته در مورد افزایش دما در سال های آتی، انتظار بر این است که میزان کشت غلات افزایش و میزان کشت حبوبات کاهش یابد. بارش متغیر دیگری است که با افزایش آن سهم سطح زیرکشت غلات افزایش و سهم سایر انواع محصولات کاهش می-یابد. درصد رطوبت بر سهم سطح زیرکشت سبزیجات و محصولات صنعتی و سرعت باد نیز بر سهم سطح زیرکشت محصولات صنعتی و غلات موثر می باشد. از این رو توصیه می گردد نحوه واکنش تولیدکنندگان محصولات زراعی سالانه به تغییرات آب و هوایی تحت سناریوهای گوناگون پیش بینی و با مقایسه مقدار تولید بالقوه با نیازهای غذایی جامعه در آینده و تعیین شکاف های موجود، مبنای سیاست گذاری های لازم در این زمینه فراهم شود. همچنین با توجه به اینکه مطالعه حاضر تنها تخصیص زمین بین انواع محصولات سالانه زراعی را مدنظر قرار داده است، توصیه می-گردد مطالعات دیگری نیز در زمینه بررسی نحوه اثرگذاری تغییرات آب و هوایی بر تولیدات سایر بخش های کشاورزی از قبیل محصولات باغی و دامی صورت گیرد.
    کلیدواژگان: آب و هوا، تخصیص زمین، محصولات سالانه زراعی، مدل لاجیت چندگانه کسری
  • حمید عزیزمحمدلو صفحات 308-322
    بازدهی نسبت به مقیاس و کشش جانشینی عوامل تولید در زمره عواملی هستند که نقش تعیین کننده ای در تقویت و یا تضعیف میزان اثرگذاری اعتبارات سرمایه گذاری در ایجاد اشتغال دارند. در این تحقیق با استفاده از داده های سال های 1353 تا 1391 تاثیر کشش جانشینی و بازدهی به مقیاس بر میزان اثرگذاری سرمایه گذاری در ایجاد اشتغال در بخش کشاورزی با استفاده از روش های حداقل مربعات معمولی، حداقل مربعات استوار و مدل های خطی تعمیم یافته برآورد گشته و مورد آزمون قرار گرفته است. یافته ها موید تاثیر مثبت بازدهی نسبت به مقیاس و تاثیر منفی کشش جانشینی عوامل تولید بر ضریب اثرگذاری سرمایه گذاری بر اشتغال بخش کشاورزی است. بنابراین تخصیص اعتبارات به زیر بخش های دارای بازدهی به مقیاس بالاتر و یا اجرای برنامه های تقویت کننده بازدهی به مقیاس و بهره وری از جمله جلوگیری از خرد شدن زمین های کشاورزی و استفاده از سیستم های نوین آبیاری، در کنار اعطای تسهیلات می تواند اثربخشی ابزار تسهیلات را در ایجاد اشتغال بهبود بخشد. همچنین تخصیص بیشتر منابع سرمایه گذاری به زیر بخش هایی که از کشش جانشینی پایین تری برخوردارند می تواند میزان اثربخشی ابزار سرمایه گذاری بر ایجاد اشتغال در بخش کشاورزی را بهبود بخشد.
    کلیدواژگان: جانشینی بین نهاده ها، مدل فضا، حالت، مسیر توسعه، مقیاس تولید
  • علی رضا کوچکی، محمد قربانی، هومن منصوری، محسن رجب زاده صفحات 323-330
    کشاورزی ارگانیک در ساده ترین تعریف به عنوان کشاورزی بدون افزودن مواد شیمیایی صنعتی تعریف شده است. با وجود گسترش شناخت و درک فواید تولید و مصرف محصولات ارگانیک در سال های اخیر، توسعه بازارهای این نوع محصولات نیازمند بررسی، تحلیل و شناخت الگوهای رفتاری مصرف کنندگان در طرف تقاضا است. در این مقاله تلاش شده است تا با بکارگیری یک الگوی پروبیت دو معادله ای با ساختار معادلات به ظاهر نامرتبط، مولفه‏های موثر بر ترجیحات مصرف کنندگان برای میوه و سبزیجات ارگانیک شناسایی شود. داده های مورد استفاده از طریق تکمیل پرسشنامه در میان 200 مصرف کننده در شهرستان مشهد در سال 1391 جمع آوری شده اند. نتایج نشان داد تحصیلات مصرف کننده، اطلاع از عرضه محصول، اهمیت ظاهر محصول و اهمیت ارزش غذایی از نظر مصرف کننده، متغیرهایی هستند که به صورت معنی دار بر احتمال وقوع همزمان تمایل به پرداخت برای میوه و سبزیجات ارگانیک موثرند.
    کلیدواژگان: ارگانیک، پروبیت چندمعادله ای، سبزیجات، مشهد، میوه
  • رضا وحدت ادب، حمید بلالی صفحات 331-344
    امروزه استفاده بهینه از منابع آبی کمیاب بخشی از اهداف اصلی برنامه های دولت در راستای نیل به توسعه پایدار در بخش کشاورزی می باشد. در این میان افزون بر مهار آب های سطحی و بهره برداری بهینه از منابع آب زیرزمینی، انتخاب شیوه آبیاری مناسب و کارا از اهمیت بسیار زیادی برخوردار می باشد. هدف از انجام این تحقیق، بررسی تاثیر برخی سناریوهای سیاستی شامل قیمت گذاری آب آبیاری و اعطای تسهیلات مالی دولت بر پذیرش روش های نوین آبیاری توسط کشاورزان از طریق مدل سازی رفتار اقتصادی آنها با تابع هدف حداکثرسازی سود است که با استفاده از مدل سازی ریاضی با بهره گیری از رهیافت پویایی سیستم صورت پذیرفت. جمع آوری داده ها و اطلاعات مورد نیاز از طریق طراحی و تکمیل پرسشنامه از نمونه ای به حجم 316 مورد از مزارع گندم شهرستان همدان در سال زراعی 95-94 انجام شد. نتایج نشان داد که سیاست افزایش قیمت آب آبیاری باعث افزایش تفاوت سودآوری در مزارع با آبیاری تحت فشار و مزارع با آبیاری سنتی گردیده و این تفاوت در سود به عنوان یک عامل اقتصادی باعث افزایش گرایش به پذیرش تکنولوژی آبیاری تحت فشار می گردد. همچنین اعطای تسهیلات مالی و کاهش نرخ سود تسهیلات، برای استفاده از آبیاری تحت فشار از سوی دولت تاثیر معنی داری بر پذیرش تکنولوژی آبیاری تحت فشار دارد.
    کلیدواژگان: آبیاری تحت فشار، پویایی سیستم، تسهیلات بانکی، قیمت آب، مدل سازی، همدان
  • فهیمه بهرامی مهنه، احمدعلی کیخا، محمود صبوحی، محمود احمدپور صفحات 345-359
    کمیابی آب برای تولیدات کشاورزی در رابطه مستقیم با امنیت غذایی به مسئله ای جهانی تبدیل شده است. به همین دلیل ضرورت استفاده پایدار از آب در دراز مدت نیازمند بکارگیری استراتژی های موثر می باشد. هدف اصلی پژوهش حاضر نیز توسعه یک سیستم حمایت تصمیم گیری برای دستیابی به سیاست ها و استراتژی های فوق در نواحی دهگانه اکولوژیکی زراعی کشور با توجه به میزان آب مجازی محصولات زراعی است. این سیستم پشتیبانی با بهره گیری از یک مدل برنامه ریزی خطی برای ارائه الگوی بهینه کشت، بررسی وضعیت فعلی منابع آب، تعیین فاصله یا شکاف غذایی، تعیین ارزش اقتصادی آب مجازی هر ناحیه به کار گرفته شد. داده های مورد نیاز از طریق پایگاه داده ای وزارت جهاد کشاورزی، وزارت نیرو و ادارات ذی ربط در ناحیه های مربوطه در سال زراعی 92-91 جمع آوری شد. به منظور دستیابی به نتایج مطلوب و دقیق، از ارزش اجتماعی محصولات و نهاده ها در مدل استفاده گردیده است. حل مدل پیشنهادی نیز در محیط نرم افزاری گمز نسخه 5/32 صورت گرفت. نتایج نشان می دهد که مقدار آب مورد استفاده توسط کشاورزان به کشت محصولات عمده در مناطق مختلف در سال 1392، 6/19میلیارد مکعب است. زاگرس مرکزی بیشترین میزان ارزش اقتصادی آب با رقم 8/3 میلیارد مکعب و ناحیه خشک مرکزی با رقم از 2/1 میلیارد مکعب آب به کمترین مصرف. نتایج همچنین حاکی از اینست که بیشترین و کمترین تغییر در ارزش اقتصادی آب آبیاری به ترتیب به گندم آبی و پنبه آبی اختصاص دارد. از دیدگاه ناحیه ای، بزرگترین و کمترین ارزش آب به ترتیب به منطقه زاگرس جنوبی و منطقه خوزستان مرتبط است. در ضمن الگوی تقاضا از طریق افزایش کشت برخی از محصولات استراتژیک، شکاف غذایی را کاهش می دهد. به منظور کاهش شکاف غذایی، یکی از راهکارهای مهم افزایش کشت گندم است لذا پیشنهاد می گردد که به منظور افزایش امنیت غذایی به همراه مدیریت صحیح منابع آب، با توجه به شرایط آبی منطقه سطح زیرکشت محصولات با نیاز آبی بالا کاهش یافته و آب اندوخته شده به محصولاتی چون گندم اختصاص یابد.
    کلیدواژگان: ارزش اقتصادی آب، الگوی بهینه کشت، برنامه ریزی خطی، شکاف غذایی
  • حسین محمدی، مرتضی محمدی، سمیه کارگر صفحات 360-369
    یکی از مهم ترین راهبردهای مورد استفاده جهت بهبود فروش محصولات غذایی، راهبرد ترفیع فروش است. تولیدکنندگان محصولات مختلف از جمله محصولات غذایی در ایران در مراحل مختلف چرخه عمر محصول از این راهبرد به شکل های متنوع بهره می گیرند. در این مطالعه به منظور بررسی عوامل موثر بر احتمال انتخاب این راهبرد در مراحل مختلف چرخه عمر محصولات صنایع غذایی ایران از الگوی لاجیت ترتیبی استفاده شده است و تاثیر متغیرهایی چون تحصیلات و تجربه مدیر، هزینه های عملیاتی شرکت، نوسانات بازار و تنوع محصولات روی احتمال انتخاب استراتژی ترفیع فروش در مراحل مختلف چرخه عمر بررسی شد. داده های مورد استفاده در این مطالعه از طریق پرسشنامه مربوط به 56 شرکت صنایع غذایی در سال 1394 در مشهد تکمیل گردید. نتایج این مطالعه نشان داد که با افزایش هزینه های عملیاتی، احتمال انتخاب راهبرد ترفیع فروش در مرحله معرفی و رشد محصول در شرایطی که سایر عوامل ثابت بماند، به ترتیب به میزان 208/0 و 5698 /0 واحد افزایش یافته و در مراحل بلوغ و افول محصول به اندازه 5481/0 و 0425/0 کاهش می یابد. همچنین با افزایش نوسانات بازار، احتمال انتخاب راهبرد ترفیع فروش در مرحله معرفی و رشد محصول زمانی که سایر عوامل ثابت باشند به ترتیب 0161/0 و 4418/0 واحد افزایش و در مرحله بلوغ و افول به ترتیب به اندازه 4249/0 و 0329/0 کاهش می یابد. به عبارت دیگر تولیدکنندگان محصولات غذایی با افزایش هزینه های عملیاتی و یا افزایش نوسانات بازار، در مراحل معرفی و رشد محصول از راهبرد ترفیع فروش با احتمال بیشتری استفاده کرده ولی در مراحل بلوغ یا افول احتمال استفاده از این راهبرد را کاهش می دهند زیرا انتخاب راهبرد ترفیع در بازاری با نوسان بیشتر و یا هزینه های عملیاتی بالاتر برای کالایی که در مرحله بلوغ و افول قرار دارد برای تولیدکننده به صرفه نخواهد بود. در ضمن هر چه تنوع محصولات تولیدکننده بیشتر باشد، احتمال استفاده از راهبردهای ترفیع فروش در مراحل ابتدایی چرخه عمر محصول یعنی معرفی و رشد بیشتر خواهد شد. از این رو پیشنهاد می گردد چنانچه تنوع محصولات تولیدکننده در ابتدا زیاد است، در مراحل اولیه چرخه عمر محصول بیشتر از راهبردهای مناسب ترفیع استفاده گردد تا ضمن شناسایی بازار مناسب، محصولات متناسب با هر بخش بازار نیز شناسایی شده و سودآوری در مراحل اولیه تولید افزایش یابد. در این خصوص باید شرکت های تولیدکننده، بودجه های مناسب را برای این موضوع تخصیص دهند. در نهایت شرکت ها در انتخاب راهبردهای مناسب ترفیع فروش، باید به مرحله چرخه عمر محصول توجه ویژه ای داشته باشند و از راهبردهایی استفاده کنند که حداقل هزینه و یا حداکثر سودآوری را متناسب با آن مرحله از چرخه عمر محصول ایجاد نماید.
    کلیدواژگان: الگوی لاجیت ترتیبی، چرخه عمر کالا، راهبرد ترفیع، صنایع غذایی ایران
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  • E. Sadeghi, R. Moghaddasi Pages 277-284
    Introduction
    Light livestock is one of the main resources of the red meat supply. In our country, annual growth rate of light livestock production is decreased by 6.4 percent in 1383 -93. In the other words, the required input price of light livestock producing have fluctuations that have much effect on producer decisions quality. Therefore, more attention to light livestock nurturing and factors that are effective on the rate of its supply is understood more than before. So, the article goals include effective factors considering on light livestock supply rate. About the studied subject, many studies have been proformed locally and globally, that include Adam (5) in South Africa, Fisher and Wall in Canada and Australia, Jezghani and Moghaddasi(7), Azizi(3) in Iran.
    Material and
    Methods
    Research seasonal data includes years 1381-91 and for three provinces of East Azerbaijan, Isfahan & Qom. Price fluctuation is investigated by GARCH models. These models are concentrated on homogenous variance contradiction (stable variance) and instead heterogeneous variance should be encountered as a problem, it is tried the heterogeneous variance is used in modeling. So, a prediction is estimated for every error period variance. The supply function has estimated in an article, is using the method of the state space model which permit seasonal, trend & unobservable cycle elements change during time randomly. The state space model is returned to standard regression model in the unobservable elements absence. The used method for the article for seasonal elements is time fixed seasonal variations.
    Data analysis: The research indicates that there is inputs prices and light livestock price. Barley price with past season lag, alfalfa price in one and two past season and the light livestock price with past season lag become significant and all GARCH coefficients in every three mentioned variant is less than one percent and significant. According to the effect of independent variants on light livestock supply in province of East Azerbaijan, it is determined that light livestock expected price has positive and significant effect, inputs expected price has negative and significant effect on light livestock supply, variance coefficient of light livestock price has negative and significant effect on light livestock supply, barely input price variance has negative and significant effect on light livestock supply. By considering the effect of independent variants on light livestock supply in Isfahan province , it is determined that expected price of light livestock has positive and a significant effect on light livestock supply, expected price of input on supply rate has negative and significant effect, variance coefficient of light livestock price has negative and significant effect on light livestock supply rates. Barely price variance has a negative and significant effect on light livestock supply. By considering the effect of independent variants on the rate of light cattle supply in Qom province, it is determined that light livestock expected price has positive and significant effect on light livestock supply rates, input expected price has negative and a significant effect on supply rate, variance coefficient of light livestock price has negative and significant effect on light livestock supply rate, barely an input price variance has negative and significant effect on light livestock supply. Summer, autumn and winter seasonal fluctuations, in a province of east Azerbaijan has a negative and significant effect on light livestock supply. Summer and autumn seasonal fluctuations in Isfahan and Qom had negative and significant effect on light livestock supply while winter seasonal fluctuation had a positive and significant effect on light livestock supply. The trend has a positive and significant effect on light livestock supply rate in three provinces. In the other words, trend fluctuation has a positive effect on supply rate. In three provinces, light livestock supply rate has positive and significant cyclic fluctuations with random coefficient in every year.
    Results
    In the provinces of East Azerbaijan, Isfahan, Qom, light livestock expected price has a positive and significant effect on its supply rate. While light livestock price variance has a negative and significant effect on its supply rate. Inputs expect price of and its variance has a negative and significant effect on its supply rate. Cyclic and trend fluctuations have a positive and significant effect on the flight cattle supply rate. Light livestock supply is less elastic than the ratio of inputs price and light livestock price change. The effect of light livestock price risk is greater than the inputs price risk.
    Keywords: GARCH process, Light livestock, State Space, Supply response
  • B. Hayati, M. Salehnia, M. Molaei Pages 285-296
    Introduction
    In recent years, most environmental evaluation studies have managed the heterogeneity of preferences among individuals. Differing sensitivities are the basis for targeted communication programs and promotions. As consumer preferences and sensitivities become more diverse, it becomes less and less efficient to consider the society in the aggregate. In this research, we will show how multilevel latent class approach is ideal for these problems as it is possible to produce group -level parameter estimates. Investment in the ecological health of the Great Lakes basin is pivotal to its long-term economic success. Lake Urmia in the northwestern corner of Iran is one of the largest permanent hyper-saline lakes in the world and the largest lake in the Middle East. The lake’s surface area has been estimated as large as 6100 km2 but since 1995 it has generally been declining and was estimated from satellite data to be only 926 km2 in 2014. Worldwide Experiences indicate that sustainability of wetlands depends primarily on the extent to which local communities are active in their management. Local communities should, therefore, be fully engaged in the conservation and management of the Lake and its satellite wetlands. Hence, we will conduct a choice experiment for investigating public preferences on the nonmarket economic benefits of Lake Urmia restoration.
    Materials And Methods
    Cluster analysis is the evolution of aggregate estimation. Clustering algorithms find groups of individuals with similar tastes among the whole sample. The preferences of the individuals are estimated in a semi-individual way by assuming that the respondent utility is equal to the cluster utility, allowing for heterogeneities across segments of respondents, but not within the cluster. The fundamental assumption of standard LC models is that observations are independent. However, this assumption is often violated for example the analysis of populations that are hierarchically structured. The multilevel model can be used to define LC models for nested data. Four attributes consist of animal habitat, climate regulation and prevention from salt storms, aesthetic and ecotourism, and education and research were considered. The required data have been collected from 13 districts located in the northwest of Iran and Exogenous stratified random sampling applied as sampling strategy.
    Results And Discussion
    The estimated model identified three lower-level groups of individuals, each with their own structure of preferences. The first class is a representation of the average individual with no highly stressed motivations and show greater variability in the responses. For class 2, the most important attribute is the climate regulation and prevention of salt storms and the cost is the least important attribute for them. It seems that the second class has an environmental concerns than others. The third class often chooses those options with no gain in environmental levels even if there is deterioration in environmental conditions. Generally, this class shows opposite opinions. The estimation process detected two grand classes in which the covariates were the factor scores from the factor analysis. Grand class 2 is a little bigger than grand class 1, and most people are in lower-level class 2, the group with the highest proportion of high well-educated young people. In this paper, a novel feature named scale-adjusting was considered and two scale classes were determined. Scale class 1 refers to lower error respondents which more than half of the people belongs to. Whereas, scale class 2 is included of less certain or higher error respondents. To summarize, people from the closer districts to Lake Urmia were classified into one specific grand class with considerable homogeneity.
    Conclusion
    Human society is complex and this complexity and its manifestations impact the preferences of individuals in potentially many ways that currently are not well-understood, but may be associated with preference heterogeneity. Thus, it seems logical to suggest that not only socioeconomic characteristics influence consumer choices, but geophysical characteristics of their surrounding environment also shape their attitudes, behaviors, and beliefs. In particular, results suggest that it may be possible to incorporate many additional individual different measures in models to capture observable heterogeneity in systematic (deterministic) utility components instead of leaving them, exclusively, to random components. Future work should be directed toward better understanding of the complex interplay of environmental choices and market choices. The results also suggest that we can explain a large part of this preference heterogeneity in the systematic (deterministic) component of utility, which in turn may help to manage a geographical area with greater citizen participation and acceptance.
    Keywords: Choice experiment, Heterogenous preferences, Lake Urmia, Multilevel latent class model, Willingness to pay
  • Gh. Dashti, Kh. Alefi, M. Ghahremanzadeh Pages 297-307
    Introduction
    The increasing global consensus built on empirical evidence, expresses that the world, is facing a threat from climate change. As a result, this can affect the agricultural sector through its productivity changes and so influence food security in the world. This can be more intuitive for countries that are dependent on agriculture. Agriculture is an important sector in Iran that provides 12 percent of gross domestic production (GDP) and 21.2 percent of employment. In this country, annual crops as an important agricultural production have 12.2 million hectare cultivation areas. They are grouped into vegetables, cereals, beans, industrials crops, forage crops and cucurbits. The shares of planted aria for these groups vary in different country's regions due to cultivation conditions differences including climatic variables. This indicates the importance of studying the climatic variable effects on these shares. Therefore, this study is aimed to assess the effect of climatic variables such as temperature, participation, humidity and wind speed on land allocation between annual crop groups in Iran's counties. This can provide useful information about the effects of climatic variable on crop shares. To achieve the purpose, using statistical methods and specifically the fractional multinomial logit model is considered. This study is benefited from advantages such as using of fractional multinomial logit model, comprehensiveness and choosing the whole country as a case study and the specific crops grouping way that distinguishes it's from the other related studies in the country.
    Materials And Methods
    Because the shares (fractions) of annual crop cultivation area for each county(observation) are limited values that vary between 0 and 1 and the sum of them is one, using of fractional models, is considered. In these models the dependant variables vary between 0 and 1, and each observation has several fractions that their summation is one. Papke and Wooldridge (1996) introduced the fractional logit and probit models that have a tow fraction for each observation. After them, Sivakumar & Bhat (2002) introduced the multinomial fractional logit model that can include more than two fractions for each observation. These models use quasi-likelihood methods for estimation of parameters and their standard errors. For estimation of the fractional multinomial logit model, this study uses Iran's 336 counties agricultural and weather information. Annual agricultural crops information is taken from the agricultural ministry and weather information is taken from the national meteorology organization. In this regard, the crops planted area shares and weather information in 1391 are used to explain the shares of annual crops planted area shares in 1392.
    Results And Discussion
    Since the weather information was on monthly scale, estimation of different models with annual crop shares variables and annualy and seasonally, Weather variables (their average, standard errors and coefficient of variation) was considered for choosing the best model based on Akaike information criterion and Bayesian information criterion. Comparing the models showed that the model with annual weather variables averages is the best. So in the next step, using the model, the marginal effects were estimated. According to the result, increasing temperature has created concerns in all fields, including the agricultural sector, affects cereals and beans productions as two important sources of food in the world. It increases the planted area share of cereals and decreases the cultivation area share of beans. The participation affects all group's cultivation area shares except cucurbits. That is the effect of cereals planted area and its share is stronger, one centigrade degree increasing of temperature increase the share of cereals cultivation area 0.02 percent. Humidity percent influences vegetables and industrial crops planted area shares and increase them. Wind speed respectively decreases and increases industrial crops and cereals cultivation area shares. According to the results also, conventional farming patterns and other agricultural system’s rules such as crop rotation in each area has important effects on the farmer's decisions on land allocations.
    Conclusion
    Based on the above results we can conclude that along with the climate changing, the annuals crops cultivation area shares and thus the amount of their production will be affected in the future. This shows the importance of using accurate methods to predict the possible values of climate variables in country's regions under different scenarios for next years. Because in this way, we can predict potential changes in the future annual crops productions and compare potential production and population food needs. This can determine the gaps between potential production and potential consumption in the future. In this regard, decreasing of agricultural sector problems in the face of climate change in the next decades would be possible by providing appropriate policies and procedures. One appropriate procedure is producing of resistant varieties of climate change results such as rising temperatures. This can define as one of the objectives of agricultural research centers. Considering that this research has studied the land allocation between annual crops, it is suggested to researchers that consider studying of other agriculture's sectors productions such as livestock and Fruit in the next research.
    Keywords: Annual crops, Climate change, Fractional multinomial logit model, Land allocation
  • H. Azizmohammadlou Pages 308-322
    Introduction
    On the approach of job creating oriented policy, taking the determinants which affect on the job creation power of investment into account, can play very effective role in enhancing the policies results. The elasticity of substitution and return to scale are two important factors which affect the efficacy of investment in job creation. Theoretically, it could be inferred that the lower the elasticity of input substitution, the higher the effectiveness of investment expenditure in the creation of job opportunities for labor forces. On the other hand, the efficacy of investment in job creation will be increased if there is increasing in the degree of return to the scale of production. This paper aims to investigate the contribution of return to scale and elasticity of substitution to the efficacy of investment in job creation in Iran agricultural sector.
    Materials And Methods
    Different econometric methods were applied to analyze the data and to estimate the presented models in this paper. Augmented Dickey Fuller (ADF) method was used to test the stationary of variables and showed that all variables are I (1). The co integration between variables was tested using Jonson Co integration approach. Jonson Co integration test results rejected the hypothesis of no Co integration between the variables of the estimated models. The values of elasticity of substitution and return to scale have been calculated for the agricultural sector by estimating the coefficients of the per capita production function using Calman Filter approach. This approach was also used to calculate the effect of the investment on employment by estimating the coefficients of the labor demand function in the agricultural sector. Next, the contribution of the elasticity of substitution and return to scale to the effect of the investment on employment in the agricultural sector has been estimated using three estimation methods including ordinary least squares, robust least squares, and generalized linear models. Required date, including agricultural sector production, agricultural sector capital, agricultural sector employment, agricultural sector wage index and interest rate were gathered from Iran central bank, and Iran statistics organization during 1974-2012.
    Results And Discussion
    The estimation results of per capita production function in agricultural sectors show that the coefficient of labor in estimated per capita production function is negative. This reveals the existence of decreasing returns to scale in this sector during the studied period. The agricultural sector has also experienced low levels of elasticity of substitution during the period and there was no significant fluctuation in the trend of substitution elasticity. According to the estimation of labor demand function for the agricultural sector, variables like investment, production and interest rate have statistically positive effect on labor demand in this sector. Wage index, however, negatively affects the labor demand and employment in the agricultural sector. Estimating the effect of a return to scale and the elasticity of substitution on the employment effects of investment, by robust least square, reveals that one unit increase in the return to scale index leads to 0.02 unit increase in the effecting coefficient of investment on employment in the agricultural sector. The elasticity of substitution, however, has a negative effect on the effecting coefficient of investment on employment, so that one unit increase in elasticity of substitution leads to 0.077 unit decrease in the effecting coefficient of investment on employment in the agricultural sector. Ordinary least squares and generalized linear models estimation also show that a one unit increase in the return to scale index leads to 0.009 unit increase in the effecting coefficient of investment on employment in the agricultural sector. Elasticity of substitution, however, has a negative effect on the effecting coefficient of investment on employment, so that one unit increase in elasticity of substitution leads to 0.06 unit decrease in the effecting coefficient of investment on employment in the agricultural sector. All findings are in line with theoretical expectation and verify the positive role of return to scale and negative role of elasticity of substitution on the employment effects of investment in the agricultural sector.
    Conclusion
    The policy making the implication of the findings is that the allocation of investment to agricultural subsectors with a higher degree of return to scale and lower degree of substitution elasticity, would enhance the efficacy of investment in job creation in the agricultural sector. Improving factor productivity via integrated the agricultural lands and utilizing new irrigation systems, in this regard, lead to enhance the degree of return to scale and increase the job creation potential of investment in this sector.
    Keywords: Expansion path, Inputs substitution, Production scale, State, space Model
  • A.R. Koocheki, M. Ghorbani, H. Mansori, M. Rajabzadeh Pages 323-330
    Introduction
    Food consumption patterns are changing as a result of health and environmental issues. Subsequently, farmers are under increasing pressure to develop and utilize less toxic production methods and pest control. Organic agriculture is a production system that sustains the health of soils, ecosystems, and people. It relies on ecological processes, biodiversity, and cycles adapted to local conditions, rather than the use of inputs with adverse effects. Organic agriculture combines tradition, innovation and science to benefit the shared environment and promote fair relationships and a good quality of life for all involved. In general, no chemicals are used on organic farms. These materials are disregarded in soil preparation, plant nutrition’s, storage, processing, and sale. In other words, organic agriculture is a kind of farming, which aims to established an integrated agriculture system which has no interference with environmental and economic benefits. Therefore, organic agriculture is the sustainable system of food production. Diverse climate and crops and animal in Iran have created potentials for the establishment and development of organic farming. However, on the production side, many farmers still hesitate to adopt organic farming due to the lack of information on market demand and the profitability of organic farming. In other words, despite benefits for this type of production in recent years development of markets requires analysis and understanding behavior pattern of consumers fruits and vegetable are very important as far as production and consumption are concerned. Based on the reports from FAO fruit production in Iran in the year 2010 were 3.5 million tons and vegetable production was 16.351 million tons. There have been a considerable number of studies on organic consumers in many countries, especially in Europe and other western countries and many studies have found a variety of factors that can potentially influence organic food consumption. Consumer behavior involves a complex and sophisticated pattern that requires marketing research in order to understand the process. The basic idea behind consumer research is the questioning of consumers about their reasons for buying, however, researchers have to go deeper and also ask people how and in which circumstances they purchase and consume. Consumer behavior consists of ideas, feelings, experiences and actions, along with additional environmental factors like advertisements and price. The major goal of this study was to model components influencing consumer’s preferences of organics fruits and vegetables in Mashhad and to provide information that is needed for the organic food industry to expand its market and improve its profitability
    Materials And Methods
    This study examines components influencing consumer’s preferences of organics fruits and vegetables using a multivariate probit model with seemingly unrelated equation. Application of multivariate probit model is normally used when two related decisions are decided upon by a decision maker or different decision makers. The model is based on this assumption that two decisions (in this study: the willingness to pay for organic fruit and for organic vegetables) have an interactive correlation. Simple random sampling was applied and total observation of 200 was selected. The data were collected by completing the questionnaire in (2012) throughout Mashhad residents. The software used for the estimation multivariate probit model was Sata 12.
    Results
    The results showed that the education level of consumers, information about the supply of organic product in Mashhad, the importance of product appearance and importance of nutrition value are variables which have a significant effect on the simultaneous probability of willingness to pay for organic fruits and vegetables. Regarding the results, attention to the promotion of product appearance, increasing the nutrition content and accessibility to the product in the market to consumers are advised.
    Conclusion
    In this study, willingness to pay higher prices for organic fruits and vegetables was examined. Due to budgetary constraints and prioritization of households to buy organic fruits or vegetables and considering the potential impact of demand for organic products on demand for other products, multivariate probit (SUR_PROBIT) was used.
    Keywords: Fruit, Multivariate probit, Organic, Vegetable
  • R. Vahdat Adab, H. Balali Pages 331-344
    Introduction
    Nowadays, efficient use of scarce water resources is one of the government’s importantgoals for dealing sustainable development in the agricultural sector. In addition to optimal exploitation and using of surface and groundwater resources, choosing of efficient types of irrigation technologies is a very important factor in sustainable water resource management. This study tries to analysis the effects of some economic policies, including irrigation water pricing and government financial facilities on farmer’s acceptance of pressurized irrigation technology in Hamedan.
    Materials And Methods
    The methodology of the research is mathematical modeling on the basis of the System Dynamics approach, by using of STELLA. A sample size of this research includes of 316 people of wheat farmers, who have selected by random method. To evaluate the reliability of the questionnaire also, firstly, a primal questionnaire was prepared and asked 30 farmers and Ranking Theta was calculated about 82 %.
    Results And Discussion
    Results showed that the policy of increasing irrigation water price, at some price levels, has not meaningful effects on farmer’s acceptance process about pressurized irrigation technology. However, this policy (irrigation water pricing), with government financial facilities such as banking facilities, has more effects on increasing of farmer economical motivation of using pressurized irrigation technology. Our results also showed that on the base scenario (current condition), the water pricing policy has more effects on acceptance of pressurized irrigation technology than the scenario in which government does not consider any financial facilities and pay any subsidy for farmers to accept and use irrigation technology. On the other hand, on the scenario without government financial supports, farmers do not have any economical motivation for acceptance of pressurized irrigation technology. In this scenario, the economical benefits of using pressurized irrigation technology of farmers, are very lower than the opportunity cost of capital used for providing and preparing of this technology, and thus, farmers do not accept this technology. The first scenario is the case without any government grants or financial supports and with no any banking facilities for farmers to use pressurized irrigation technology. In the second scenario, 50 percent of pressurized irrigation technology, performance costs are paid through loans by the supportive interest rate of 5 percent yearly. The third scenario introduces a current condition, including government grant and subsidized loans, and the fourth scenario contains the condition in which 50 percent of irrigation technology’s implementation cost is paid by government grants. Results showed that in the first scenario, at all levels of irrigation water price, the benefits of technology acceptance are lower than acceptance opportunity cost, and thus farmers of the study area do not have any economical motivation to use pressurized irrigation technology. But only at the irrigation water price of 1200 rials for one m3 of irrigation water, farmers accept to provide, implement and use pressurized irrigation. In the second scenario, in which 50 percent of pressurized irrigation technology performance costs are paid through loans by the supportive interest rate of 5 percent yearly, the farmers will accept the technology at all level of irrigation water prices. In the third and fourth scenarios also, farmers accept the technology in all levels of irrigation water prices. Results showed that the policy of increasing irrigation water price, at some price levels, has not alone meaningful effects on farmer’s acceptance process about pressurized irrigation technology. But, this policy (irrigation water pricing), with government financial facilities such as banking facilities, has more effects on increasing of farmer economical motivation of pressurized irrigation technology using. Results showed also that on the base scenario (current condition), the water pricing policy has more effects on acceptance of pressurized irrigation technology than the scenario in which government does not consider any financial facilities and pay any subsidy for farmers to accept and using irrigation technology. on the other hand, on the scenario without government financial supports, farmers do not have any economical motivation to acceptance of pressurized irrigation technology. In this scenario, the economical benefits of using pressurized irrigation technology of farmers, are very lower than the opportunity cost of capital used for providing and preparing of this technology, and thus, farmers do not accept this technology. Results also, showed that economic variables of reduction of water consumption costs, land leveling costs reduction, financial ability of farmers, adequacy of loan amount have important and meaningful effects on irrigation technology acceptance.
    Conclusion
    The policy of increasing irrigation water price, at some price levels, has not meaningful effects on farmer’s acceptance process about pressurized irrigation technology. however, this policy (irrigation water pricing), with government financial facilities such as banking facilities, has more effects on increasing of farmers economical motivation of using pressurized irrigation technology.
    Keywords: Financial facilities, Hamedan, Modelling, Pressurized irrigation technology, System dynamics, Water price
  • F. Bahrami Mehneh, A. A. Keikhah, M. Sabouhi, M. Ahmadpour Pages 345-359
    Introduction
    Water scarcity has become a global issue due to its direct relationship with food security. For this reason, the need for the long-term sustainable use of water necessitates the application of effective strategies. In this regard, strategic programs are utilized in water resource management and agricultural policies in order to increase self-sufficiency, to reduce the food gap, to decrease the cultivation of water based products, to maximize the economic value of water and to guarantee efficient allocation of resources among different activities in most parts of the world. The main objective of this study is to develop a decision support system to achieve the above-mentioned policies and strategies in the ten agricultural and ecological zones in the country according to the amount of virtual water for crop production.
    Data and
    Methods
    The decision support system seeks to introduce an optimum pattern and to investigate the current status of water resources and determine the food gap and virtual economic value by means of a linear programming model. It intends also to determine the return on investment of crop production in each region. Our goal of this research is to maximize the value of virtual water with respect to land and availability of surface water and groundwater constraints. We also consider socio-economic constraints to ensure minimum and maximum area under cultivation in every region. In order to achieve accurate results, the social value of goods and inputs has been used in the model. In determining the social value of all goods and tradable inputs, prices of the border with a shadow exchange rate are used. Given the importance of addressing the amount of water used to produce goods, the virtual water content of products on maximizing the economic value of water is used in this study. Due to climatic conditions and consequently the performance of production in different regions, we use water requirement to crop yield ratio for every region for calculation of the virtual water content of a product. In this study, water valuation was based on value added inputs, while social values were used as criteria in its calculation. The data are gathered from the database of the Ministry of Agriculture, Ministry of Energy and the relevant agencies in the region. We used the 32.5 Edition of GAMS software to estimate the proposed model.
    Results
    The results show the amount of water used by farmers to grow major crops in different regions in 1392, was 19 billion cubic meters. Central Zagros with 3.8 billion cubic meters and the Central dry zone with 1.2 billion cubic meters have respectively the largest and smallest water consumption. The results also showed the greatest change and lowest change in economic value of irrigation water related to wet wheat and wet cotton respectively. The regional view, the greatest and the lowest value of water refers respectively to the South Zagros region and the region of Khuzestan. Research results show that the pattern of demand reduces the food gap through increased cultivation of some strategic products. In order to reduce the food gap, one of the most important strategies is the increased cultivation of the wheat crop.
    Conclusion
    This study provided a cultivating pattern in order to meet two important goals: cutting water consumption and reducing the food gap by increasing the cultivation of strategic crops such as wheat. In fact, by implementing appropriate Logistic policies, the government and politicians can achieve the aforementioned objectives by diversifying the current cultivation pattern in the desired region in compliance with environmental, economic and food security and health security considerations. The economic value of irrigation water and reduction of the area under cultivation is also a consequence of the proposed program. Instead of providing constant value in all regions of a country, providing an optimal cultivation pattern while considering the exact value of virtual water is a better policy. The proposed cropping pattern reduces Food gap and the area of water-based production cultivation and reduces water consumption, which can be used for producing strategic crops. The proposed cropping pattern increases the economic value of water by 20%. Indeed, it suggests that acreage crops such as wheat, pulses, and oil seeds are increased and rice and sugar beet cultivation is decreased. The main objective of the proposed cropping patterns to reduce the food gap and increase the welfare of consumers.
    Keywords: Economic value of water, Optimum cropping pattern, Food gap, Linear programing
  • H. Mohammadi, M. Mohammadi, S. Kargar Pages 360-369
    Introduction
    Food industry is one of the most important industries in developing countries that has an enormous role in employment, export and value added of the agricultural sector. Iran as a developing country has a comparative advantage in food product industries for several reasons such as adequate and cheap raw materials and having several companies in the field of food industries. The food products, sales promotion strategy is one of the strategies used to promote the sale of products in different stages of product life cycle. Appropriate usage of promotional strategy in different stages of product life cycle has an important role in the profitability of these industries and so determining the factors affecting the selection of promotion strategy in different stages of product life cycle is important. In this study, the main objective is to determine factors affecting the selection of promotion strategy in different stages of product life cycle in food product industries in Mashhad, Iran.
    Materials And Methods
    The main aim of this study is to determine factors affecting the selection of promotion strategy in different stages of introduction, growth, maturity and decline in food products industries in Mashhad. For achieving this goal, some explanatory variables such as education manager, company experience in food industry, operational cost, product diversity and market fluctuations considered as independent variables and ordered logit model was used for analyzing the effect of these variables on the probability of selecting different categories of a dependent variable. Dependent variable has four categories and shows the stage of product life cycle that managers select for applying promotion strategy.
    Results And Discussion
    One of the most important strategies for increasing sales in food product industries is sales promotion. Producers used this strategy, according to the life cycle stages of their products. In this study, for determining the important factors that affect the probability of selecting promotion strategy in different stages of product life cycle, we used ordered logit model in Mashhad food products companies. The results show that variables such as education of managers and company experience in producing food products have not any significant effect on choosing promotion strategy at different stages of product life cycle. Furthermore, operational costs and market fluctuations have a negative and significant effect on choosing promotion strategy in different stages of product life cycle. Therefore, when operational costs increase or when market fluctuations exist, producers in the food product industries apply promotion strategy mainly in the introduction and growth stages of product life cycle and the possibility of using promotion strategy in maturity or decline phase decreases because selecting promotion strategy in markets with high volatility or increasing operational cost is not economical. On the other hand, products diversity has a different pattern and with more diversity of products, the possibility of using promotion strategy in maturity and decline stages of product life cycle increases. It is recommended that if products diversity is high, producers use the appropriate promotion strategy at each stage of product life cycles and with identifying appropriate markets and products, profitability would increase in these phases. Companies should consider a sufficient budget for this subject. With increasing market volatility and operational costs, producers try to introduce and sell more products and increase the possibility of using marketing mix in the earlier stages of product life cycle. Diversity has a different pattern and perhaps the reason is that there is an interaction between the promotion strategy and diversity. Producers in the introduction and growth stages spend their costs for product introduction through advertising and replace more advertising instead of promotional strategies. However, in maturity and decline stages, the usage of promotional strategies increases because there are enough products in the market and producers try to sell their products by different promotional strategies. The promotional strategy will apply when consumers through advertising finds sufficient knowledge of the product, and then because of the promotion in buying this product, increase their purchases.
    Conclusion
    Because using appropriate marketing mix have a considerable effect on the profitability of companies, determining the appropriate marketing mix in each stage of product life cycle is essential. Promotion strategy has a substantial role in the profitability of food products companies and according to this research, the following recommendation might be important. At first, each producer should select an appropriate promotion strategy in each phase of product life cycle and then companies should devote adequate budget for research and strength the efficiencies of each marketing strategy such as promotion in each stage of product life cycle.
    Keywords: Food industry Iran, Ordered logit model, Product life cycle, Promotion strategy