جستجوی مقالات مرتبط با کلیدواژه « داده های تابلویی » در نشریات گروه « اقتصاد کشاورزی »

Extended Abstract

Introduction and

The agricultural sector is one of the most important economic sectors in every country, which in Iran has significant advantages such as land diversity, cheap labor, and less need for complex technology to produce all kinds of products in different seasons of the year. Therefore, it,s maded strengthening is essential for economic development, employment, and increasing non-oil exports. This article investigates the factors affecting the trade of agricultural products between Iran and the Russian Federation using the gravity model.

First, necessary statistics and information were collected from the websites of the Central Bank and the World Bank for the period from 2010 to 2020. Then, in order to investigate the influencing factors on the volume of bilateral trade of agricultural products of Iran and Russia, the generalized gravity model was used. Before estimating the model, first the reliability of the variables was checked through the Levin-Lin and Chu test, and then the gravity model was estimated using the panel data method. In this study, the data were used separately for the export sector, once for import and finally for the whole trade (exports + imports) to determine the effects of different variables on each sector. Then, the Hausman test results were analyzed to select the most suitable part for analyzing the results.

The results of Levin-Lin and Chow tests showed that all variables were significant and panel data were static. The estimated results of the gravity model for the three sections under study are statistically significant based on F-statistics. Therefore, the null hypothesis is rejected, indicating that the intercepts are different from different time periods and panel data should be used. The results of the Hausman test for exports, imports, and trade were calculated as 0.214, 0.4359, and 0.000 respectively, based on which trade estimation was selected for analyzing the results. Estimating the gravity model for trade indicated that the coefficient of the variable Gross Domestic Product (GDP) of both countries, which represents their economic size, is an important factor in the bilateral trade volume of agricultural products between Iran and Russia. Also, distance, real exchange rate, and virtual variable of membership in the Eurasian Economic Union are the effective factors in the bilateral trade volume of agricultural products between Iran and Russia.

Generally, increasing the Gross Domestic Product (GDP) of both countries leads to an increase in bilateral trade of agricultural products between Iran and the Russian Federation. Therefore, it is suggested that measures be taken in the decision-making of policy makers in the field of membership in organizations and commercial agreements, especially in the field of agriculture.

Carbon dioxide emission is one of important challenges facing humanity, which has attracted the attention of many researchers and policymakers in recent years. The purpose of this study is investigating the factors influencing carbon dioxide emission. For achieving the purpose of paper spatial econometrics model and panel data of MENA countries are used over the period of 2000-2015. The results indicate that carbon dioxide emission in the MENA region countries have significant effect on surrounding countries. Also, the variables of energy consumption (0.01), economic globalization (0.134), industrialization (0.405) and urbanization (0.042) have positive and significant effect on carbon dioxide emission in the MENA region. The interaction among energy consumption and globalization (0.361), energy consumption and, industrialization (0.234) and urbanization (0.085) have a positive and significant effect on carbon dioxide emission. According to the results of this study, it is necessary that policymakers should not only focus on the national economic benefits but also consider the national and regional environmental benefits in policy making.

Poverty reduction is one of the important goals of development programs. This study was conducted to investigate the factors affecting rural poverty in provinces of Iran during the years 2011-2018. Poverty Gap Index has been calculated as dependent variable. The log- log regression model of influencing factors on poverty was estimated using the cross section weighted least squares method. Results showed that rural poverty has been an unbalanced long- run phenomenon that has grown over time and covered more people. The coefficients of estimated model showed that the share of province in GDP, areas under cultivation, number of rural comprehensive health service centers and dummy variable of less poor provinces have had significant negative effect on poverty. The value added of agriculture sector, rural consumer price index, family size, trend, first lag of dependent variable and dummy variable of poorer provinces have had significant positive effect on poverty gap index. The negative effect of the share of province in GDP and areas under cultivation on poverty confirmed the important role of production infrastructures and economic opportunities in poverty reduction. Significant positive effect of the value added of agriculture sector can be an evidence of small contribution of villagers in value added of this sector. Based on the results of this study, it is suggested to avoid the concentration of investment, resources and production opportunities in richer provinces and to pay attention to balanced regional development to reduce poverty in poor provinces. Also anti-inflationary policies will reduce poverty in all regions. Since poverty has been a long-run and growing phenomenon in most regions, long- run planning in production and welfare infrastructures is needed to eradicate poverty.

This paper aimed to examine the effects of ICT developments on the renewable energy consumption in the economic sectors of Iran. The panel data for study were obtained from three sectors of agriculture, industry, and services within the 2000-2016 timeframe; the unit-root test showed that the variables were both stationary and nonstationary. As a result, the mean group was used to estimate the long-run effects, and it revealed that, in the long run, the increase in the number of the Internet and cellphone users decreases the renewable energy consumption. In addition, the GDP and investment growth increases the energy consumption, because the growth of information and communication technology infrastructures develops the e-government and teleworking and reduces the traffic, and, in turn, conserves the energy. However, the increase in the number of landline and cellphone users in the short run increases the energy consumption. The GDP increase will also raise the energy consumption in the short run.

Optimal use of energy inputs and increasing productivity of energy lead to less production costs, less greenhouse gas emission also, less negative effects of agricultural inputs on the environment. This study aims to examine the energy balance of sugar beet production in Iran and compares the economic and environmental dimensions of expanding sugar beet production. For this purpose, production function of sugar beet was estimated using Panel data of five provinces of Hamedan, Kermanshah, Khorasan Razavi, Fars and West Azerbaijan for 2000-2015 period. Results showed that the highest energy inputs are chemical fertilizer, machinery and labor, respectively. Also, with a net energy gain of about 643 GJ, 23.53 energy ratio and 1.4 MJ/Kg energy productivity, an increase in sugar beet production is desirable in viewpoint of energy balance. The estimated Cobb- Douglas production function showed that only machinery and farmyard manure were used in the economic range. The MPPs of two inputs of machinery and farmyard manure were higher than other inputs. Also, an increase in sugar beet yield using these two inputs causes less CO2 emission. The significant coefficient of Dummy variable showed that the yield of sugar beet in Fars and Khorasan provinces is significantly lower than other provinces. The sum of the significant coefficients of the energy inputs indicated a decreasing returns to scale. Based on the results of this study, expanding mechanized cultivation and optimal use of monogram seeds, also, reducing subsidies and realizing the price of chemical fertilizers to reduce the use of this input are suggested.

One of the most important issues in the world literature is to measure and assess the degree of competitiveness and monopoly in the markets and determine the structure of the international market. One of the main goals of countries in the world of trade has long been gaining a greater share of the international market. Iran is one of the largest pomegranate producers and exporters in the world. The present study evaluates Iran's pomegranate demand by using parametric models and panel data for countries exporting pomegranates from Iran during the period of 1993 to 2013. The results showed that the price elasticity of the pomegranate demand is -0.06. This means that as prices rise, there is no significant reduction in the demand of the importing countries, and it shows demand of Iran pomegranate in the global market is inelastic. These results are consistent with the calculation indices of the Herfindahl – Hirschman, share of two largest firms and eight largest firms in the pomegranate world market structure, which highlights the strong focus of the market for Iran and India. It seems that that the continuation of the current process may endanger Iran's market power and position. Finding new business models, marketing and participating in international exhibitions are some of the strategies to maintain and expand Iran's pomegranate demand in global markets.

Agricultural commodity export is a main attribute of developing countries and it is the basic force of development, however, developing countries have faced domestic and international instability in their markets and monetary and fiscal policies and these instabilities create a difficult condition for most of producers and exporters. Volatility in exchange market is one of the most important factor and vital concentrate for international trade especially agricultural commodity export. Because of this concern many studies have been conducted in this filed; (Aristotelous, 2001; Chen, 2009 and Sabuhoi and Piri, 2009) .Many of these studies has stated that exchange rate fluctuation has a negative impact on aggregated agricultural export; however, none of them has been focused on the effects of exchange rate fluctuation on exported value of important commodities in long run and short run. In recent years, exchange rate fluctuation has been raised about 6 percent since 2007 to 2010 and it seemed that this phenomenon has a negative impact on agricultural commodity export in Iran. To test this hypothesis exported value of three important commodity (date, orange and grape) and exchange rate volatility since 1970 to 2013 have been used.
Material and

In order to examine the relation between real exchange rate volatility and export values of date, orange and grapes, first GARCH method has been used to draw out exchange rate volatility; then, Panel unite root test has been used to check the level of integration. Since real exchange rate is not heterogeneous for different cross sections Levi-Lin and Chow unit root test has been used for this variable and IPS test has been applied to export value. Pederoni co-integration test has been used to check the integration between these variables. Finally, FMOLS (Fully Modified Ordinary Least Square) and DOLS (Dynamic Ordinary Least Square) methods have been used to estimate long run and short run coefficients.

Main results showed that real exchange rate volatility and export value of selected commodities are Co-integrated. The coefficient estimation of FMOLS and DOLS methods are equal and statically significant; so, these methods aren’t statically different and they showed that real exchange rate volatility has a negative impact on exported value for whole panel. However, the specific coefficient for each commodity showed contradictory behavior in short run and long run; for example real exchange rate fluctuation has a negative and significant impact on all the commodities; but, in short run this variable has a positive and significant impact on exported value. Moreover, based on estimated results it seems that fluctuation in exchange market has a greater impact on more valuable commodities like date.

Considering the importance of agricultural product trade and in order to overcome mono-product economy, this study investigated long term and short term relation between export of grape, orange, date and exchange rate volatilities. To this aim, first the index of exchange volatility using generated autoregressive conditional heteroscedasticity (GARCH) was calculated. In order to investigate the relation between exchange rate volatilities and export value of agricultural product, unit root test and cointegration test related to panel data were used during years 1971-2013. The results of model estimation showed that exchange rate volatilities in short term and long term have respectively positive and negative effects on the export value of orange, grape and date. In long term, the negative effects of Exchange rate volatilities on high-export-value products are more than its effects on low-export-value products. Based on the estimation results we can conclude that, in short run, exporters are willing to increase their interchange and gain profits of the volatility in exchange market; however, in long run exchange rate fluctuation has effect on their long run profit because of instability in price and production, especially for more valuable products. Moreover, these risks can be more harmful in long run because of its impact on investment and production and due to lack of production, most of Iranian exporters will lose their international markets, hence, their volume and values of agricultural commodities export will reduce gradually. Based on the results, Iranian government should create a stable economic condition in long run, present proper information about exchange market future trend and its fluctuation in long run and short run and create a better marketing condition in short run.

Exchange rate volatility is ambiguous and the one of the factors that effecting agricultural trade. Regarding to importance of free trade and economic monoculture crops, the purpose of this study was to investigate the effect of exchange rate uncertainty on the foreign trade of agricultural products for this purpose four crops (pistachio, dates, raisins and walnuts) were selected and required information were gathered for period 1980-2010. For this purpose, first for calculating the uncertainty of exchange rates, generalized auto regressive conditional dissonance variance model (GARCH) were used and then to estimate the relationship between exchange rate and export of agricultural products were used gravity model and panel data method. The results of study showed that the exchange rate uncertainty has a negative effect on the export of agricultural products and pistachios are affected by this uncertainty more than other products. Therefore, creating certainty in the currency markets can be developed important agricultural export products. Also, other results showed that income importing countries has a significant and positive impact on export volumes that should be noted the selection of target markets.

Developing countries, including Iran, have a high degree of volatility of macroeconomic variables. Fluctuations inex change rate, bank interest rate and inflation rate can create insecure environment for in vestorsin Iran. Hence, this study examined the impact of macroeconomic variables on the Tobin’s Q index for the Sugar companies of Tehran Stock Exchange (TSE) during the period between1380-1390. A panel data model in the form of random-effects analysis was performed. The results indicate that the exchange rate, inflation rate and therate of return onassetshavean insignificant negative impact on the Tobin’s Q index. Bank interest rateshave a significant negative impact, while Market value has a significant positive impact on the Tobin’s Q index.

For many years، Iran has traditionally been the largest pistachio producer and exporter in the world. In addition، pistachio is considered as one of the important sources of foreign exchange earnings and it has important role in reducing dependence of the public budget on oil revenues. Given the importance of pistachio in the Iran''s agricultural economy، it is essential to identify the factors that aaffects pistachio exports. The main purpose of present paper is to estimate the export demand function for Iranian pistachio. Using a panel of seven destination markets (including Australia، France، Germany، Japan، Malaysia، Mexico and Switzerland) over the period 1992–2012 and controlling for the endogeneity of the explanatory variables، error component two stage least squares method is used to estimate export demand function. According to the results، all estimated coefficients are significantly different from zero at the five percent level and have the theoretically expected signs. The results show that long-run elasticity of demand for Iran''s pistachio exports with respect to relative prices and real exchange rate changes are considerably greater (in absolute terms) than their corresponding short-run elasticity. The results also suggest that the demand for Iran''s pistachio exports is inelastic with respect to real foreign income in both short- and long-run. Thus، with respect to demand conditions in destination markets، it is necessary to reduce marginal cost of Iranian pistachio producers by elaboration and implementation supportive policies.

Urbanization، population growth and moving from traditional manufacturing industry to accelerate the process of economic development and parallel، significant environmental impacts are left. The purpose of this study is to investigate the effect of different variables such as trade openness، comparative advantage، production levels and other important variables affecting the emission of carbon dioxide gas in various countries of the world. Stata11 software was used to estimate the panel data model of 77 countries over the years 2010-1980. The results indicate that propagation environment، and in particular CO2، in all four groups of countries are associated with prior emission، with a per capita income direct link but with the square of it correlates inversely and have direct link with the ratio of capital to labor and with the square of it correlates inversely and trade openness in high-income countries and moderate negative effect in low-income and middle-income countries is directly related to the bottom.

This paper investigates the effects of advertising، profitability، degree of concentration on the market and Research & Development costs on the Market Share in the Iranian large food and beverage industries during the period of 2000-2011. For this purpose، the study used the statistics associated with large firms-with more than 50 employees. The panel data technique was used to estimate the model. The main results of this paper reveal that، the elasticity for market share with respect to profitability is greater than thoes for other explanatory variables such as advertising cost and R&D cost. Moreover the results indicate that concentration on the market has a positive and significant effect on the Market Share within the large industries. Thus،the main policy recommendations of this study is that Firms and business managers and executives as well as economic authorities can contribute to improve market share through providing the essential conditions to increase the research and development costs، advertising costs، and increase in profitability in the Iranian large beverage industries.

With respect to impotance of transportation in marketing of agricultural products، this paper aims to assess transportation infrastructure development effect on value added of agricultural sector in selected Iranian provinces using Panel Data model (fixed effect method) in 2000-2011 period. The results show that transportation infrastructure index has positive effect on growth of agriculture sector. It is concluded that with respect the positive effect of transportation on added value of agriculture، investment in this area should be emphasized in the country development strategy and part of its cost could be covered by imposing income tax on commercial agricultural producers.

As the world trade is growing، exchange rate acts as a bridge between different economies and its volatility can affect price level، output، exports and imports. The purpose of this study is to investigate the effects of real exchange rate volatility on the export demand for the two products of apple and potato in the nine developing counteries of producing and exporting the two products during the period of 1992-2009 years. To achieve the goal، using Autoregressive Conditional Heteroskedasticity (ARCH) model، the real exchange rate volatility was estimated. Then the effects of exchange rate volatility on the export demand for apple and potato were analysed based on the panel data approach. The results indicate positive effects of real exchange rate and negative effects of real exchange rate volatility on the export demand. The weighted average income of importing countries has a positive effect and the relative export price of apple and potato has a negative effect on the export demand.

This article is to analyze and determine the level of agricultural development and the amount of imbalance in the rural areas in West Azerbaijan province and districts for the years from 2001 to 2009. To achieve this goal، 48 defined developed indicators using two methods، factor analysis method and numerical taxonomy were measured. The provinces in terms of degree of development in the agricultural sector were ranked. On the other hand، the effect of bank keshavarzi’s microfinance on agricultural development was measured with using a panel data model in same province for the years from 2002 to 2008. The results show that the levels of agricultural development districts of West Azerbaijan province during the years studied، from 2001 to 2009 the level of agricultural development has reduced. By the way the results with fixed effect show that the effect of bank keshavarzi’s microfinance on agricultural development is positive and significant.

Note that the overall agricultural economy in some developing countries are affected by government policies, not the free market, studding role and government indicators on agricultural production and productivity is important. Hence In this study, the role of government on production and productivity of agricultural inputs has been studied by using the World Bank indicators for APO contries in 2002-2010. So production and structural equation methods was used to test the hypothesis. The results of the two methods confirms the hypothesis. Results showed that a country with better government policies can be more agricultural production and labor creates more production in a country with better government policies. Appropriate government policies can also improve indirectly excitation agricultural productivity by investing in agriculture. So suggested that focus on improving performance and the control of corruption government index.