مجله اقتصاد محیط زیست و منابع طبیعی
پیاپی 3 (بهار 1396)

Considering, the effect of social capital on the improvement of quality of    environment and sustainable development, the main goal of this study is the investigation of relation of Granger Causality between two varieties, social capital and emission of CO2, in Iran. In this study, using data in the period of 1978-2009, the relation of Granger Causality has  been studied via 3 methods of Hsiao’s Granger Causality, Toda and Yamamato, and Bound Testing. The results of this study established a one way relation of Causality of social capital and CO2 emission in Iran. As a result, this study shows that social capital has a significant role to play in reduction of air pollution.

The purpose of this study is to investigate the asymmetric effects of crude oil prices on oil stocks in OPEC member countries. Indeed, in this research, the effects of positive and negative shocks of OPEC crude oil prices on OPEC's oil reserves index have been studied using the non-linear distributed autoregressive model (NARDL) during the period of 1980 to 2015.The results show that the effects of positive and negative shocks of crude oil prices on oil reserves life in short run for Venezuela are asymmetric; for Iran, Libya, the United Arab Emirates, Angola and Ecuador in long run are asymmetric; for Saudi Arabia and Kuwait in both short run and long run are asymmetric, and finally symmetric for Iraq, Qatar, Nigeria and Algeria countries. Also, the results of the model show that the effect of negative oil price shocks on oil reserves life of these countries (exclude Libya) is higher than positive oil price shocks. The results of the cumulative asymmetric effect of oil price shocks on the oil reserves life show that response of the oil reserves life of Saudi Arabia and Kuwait to the asymmetric oil price shocks is different from that of other OPEC members, because the asymmetric oil price shocks have a permanent and significantly negative effect on their oil reserves life. While this effect is temporary and positive for Venezuela and temporary and negative for Libya, it is not statistically significant for other countries.

In this study, by utilizing the Ecological Footprint (EF) as an environmental sustainability indicator in context of Environmental Kuznets Curve (EKC), the effect of economic growth on environmental sustainability in Iran was examined. To achieve this goal, an environmental degradation model is established during the period of 1985–2013. Furthermore, the long and short run relationships between EF and per capita Gross Domestic Production (GDP), energy consumption per capita, population intensity and trade openness were investigated by applying Autoregressive Distributed Lag (ARDL) approach. The empirical results revealed that the relationship between EF and economic growth is inverted U-shaped and statistically significant. Moreover, a 10% increase in population intensity is linked with 11.2% and 9.6% growth in EF in long and short run, respectively. Although the impact of trade openness is positive on EF and statistically significant in long run, there is not significant impact in short run. Furthermore, a 10% increase in energy consumption is linked with 4.6% and 3.9% growth in EF in long and short run, respectively. The result shows the desirability of energy consumption efficiency, developing clean energy, lowering urban intensity and improving environmental monitoring.

This article examines the robust determinants of military expenditure in the MENA region countries (including Iran) with an emphasis on natural resources during the years of 1995-2014. For this purpose, 22 variables in three categories are used: 1.Economic and social variables 2.Political, strategic and military variables 3.Natural resources. Bayesian Model Averaging approach (BMA) is used, due to convenience feature to consider the uncertainty assumption of model. With estimation of 100000 regressions and Bayesian averaging of coefficients, robust determinants of military expenditure in the MENA region countries are specified. Based on the results, the share of natural resources revenues from GDP and the share of fuel exports from commodity exports have an important effect on military expenditure with positive signs. Among the natural resources, the share of oil revenues from GDP has a positive and robust effect on the military expenditure with a probability about 0.99. According to the others results, among the political, strategic and military variables, the variables of terrorist incidents, warfare score and the average military expenditures of the MENA region countries, respectively, have important influence on military expenditure. Also, none of the economic and social variables have significance and probability level requirement to influence on military expenditure. Accordingly, it can be said that strategic factors (war and security threats) and rents of natural resources (especially oil) are the factors determining the military expenditure in the MENA region countries.

Most economic activities inevitably use natural resources and at the same time by releasing waste material which is a result of production activities, imposes pressures on the natural ecosystem. In this study it has been attempted to investigate the relations between carbon dioxide emissions and national income variables, trade liberalization, electricity generation, total consumption of petroleum products, natural gas consumption and domestic investment in the form of Environmental Kuznets Curve (EKC) hypothesis by applying time series data of Iran’s economy during the time period of (1979-2010) and by adopting Auto Regressive Distributed Lag (ARDL) method. This shows that environmental hypothesis and Kuznets Curve are partly approved in Iran. In order to accomplish this issue thoroughly, standard growth and perfect technology in production is required. The results of this study indicate that increase in national income, trade liberalization, electricity generation, total consumption of petroleum products,  natural gas consumption and domestic investment have a positive and significant effect on carbon dioxide emission. Moreover, it has been found that chi-income has a negative, however, more insignificant, compared to income, on environmental pollution

Shushtar waterfalls as one of the ecotourism and geotourism attractions in Khuzestan province, is an important tourism area in Iran. Therefore, study of importance of the natural landscape and historic structures can be useful in forecast needs, removal of shortages and tourism development in the region. In this study willingness to pay by visitors to this site is calculated.. We use contingent valuation method and dichotomous choice questionnaire for this purpose. Samplers were conducted using the 300 questionnaires randomly from the Shushtar’s people in spring 2014. Logit regression model was used in order to estimate the willingness to pay. Average willingness to pay was estimated about 18351.26 Rial and due to the average number of visiting per year, 2.9 times per year, the annual payment have been obtained about 168831.59 Rial for each person. The results shows that the following variables, age, gender, household size, education, income and offered price have significant effects on people's willingness to pay. In the meantime, variables of age, gender, household size and offered price have negative effect and two variables of income and level of education have a positive impact on willingness to pay.