مجله اقتصاد منابع طبیعی
پیاپی 1 (پاییز 1391)

Water resources are considered as a capital good as well as natural resources. Since، water resources create services for sectors such as municipalities، agriculture، industrial activities and recreation، then is considered as a capital good. Because it is a gift of nature and scarce at the same times، it is considered as a natural resources. This natural asset is a not replaceable and is a valuable good for economic development and societal development. Also it is important element in keeping economic equilibrium، stability of ecosystem and quality of environment. With due attention to demand water and supply، economists can come up with right decisions to deal with scarcity of water resources. There are good enough papers about demand for water in different sector such as municipalities، agriculture and industry. But considering that water is transferable، from one sector to another، then we need to estimate aggregate demand for water rather than considering it separately function. In this paper، aggregated demand for water، first in the context of simultaneities system of equations is evaluated and secondly، evaluates aggregated demand with classification for the variables affecting the demand. At the end quantity supplied and demanded and equilibrium prices are forecasted for 1390 to 1400 and for the province of Esfahan. Some finding of the research are that، there are a positive connection between consumer income and aggregated demand for water، land and water are complement inputs and labor and water are substitution inputs.

In recent decades different ways has been proposed to internalize externalities or to estimate the WTP. The choice experiment is the following sets of choice modeling and stated preference family and it is a systematic method of producing data. This article outlines the various methods of valuing non-market and environmental commodity then describes the choice experiment. How to define the attributes and levels، statistical design، building choice sets and design questionnaire are described. To build an economic model for this method Lancaster''s theory of value and Random utility theory with regard to Weibull or Gumbel distribution are explained. Conditional، polynomials، mixed logi tmodel، logit with random parameters model and to use a nested logit، the IIA property and how to test Housman-Mac Fadden are discussed. logit model estimates with 1296 observations that extract from 300 visitors in Hamedan’s Ganjname site in 2010 summer. Research suggests that the choice experiment method has a wide superiority than other valuation methods in gathering data، select a model، coefficient estimation and WTP and WTA derivation.

One of the most important resources in providing healthy environment is natural resources such as forests and pastures. In this study، based on the latest data on regional accounts published in 2012 by the Statistical Center of Iran، the paperuses the so-called value added comparative advantage of forestry in provinces of Iran to calculate the Revealed Comparative Advantage (RCA). The paper also deals with theimpactof comparative advantage of forestry on economic development during the fourth development plan. The resultsshow that the Mazandaran، Golestan، Sistan&Baluchestan، Chaharmahal&Bakhtiari and Ghilan enjoy higher comparative advantage respectively during the Iran’s fourth development plan. Also، based on Panel data regression our findingsdid not support a positive relationship between value added comparative advantage of forestry and economic development in provinces of Iran. This indicates that other economic sectors may have played more crucial role than forestry in economic development of the provinces.

Mirages as one of the renewable water resources of province are considered as ecotourism attractions. The water of these mirages has agriculture and tourism consumption. In tourism aspect، the mirages have the potentials such as fishing، observing plant and animal species، sailing، water skiing and other water activities. Using field data survey in the system model of Jin Ying Deng (EP)، this study aims to evaluate the water resources potential of mirages of Kermanshah Province for the development of economic - ecotourism activities. Required data was collected and analyzed through descriptive – analytic method and field data survey. According to the results of study، chosen mirages are divided into 6 groups in the way that Bistoon، Taqebostan، Niloofar، and Ravansar mirages got the most points and have the most ecotourism potential. Since mirages are considered as renewable water resources، by observing the ecological and environmental principles of the area، it is possible to increase the relative welfare and as a result the economic power of the province through economic investing for various exploitations such as tourism.

In recent years، following the rising demand and supply of natural gas، economists have studied Natural gas market. Gas exporter and importer countries are involved in special policy so as to maximize their profit. One of such policies، which have been made by gas exporter countries، is foundation of “Gas Exporting Countries Forum” (GECF). Estimating of demand for GECF’s produced natural gas can be considered as one of the important tools to maximize the profit of GECF. In this paper، long-run residual demand function for GECF’s produced gas is estimated. In this regard، the yearly data over the period 1980-2010 are employed. Results indicate that the residual demand for GECF has positive relationship with gas price as well as the fact that there is positive relationship with time trend. Such that a dollar increase in gas prices، GECF’s demand decreases for four trillion cubic meters of gas per year; And demand for the GECF’s gas average annual increase of 0. 3 trillion cubic meters.

Although، environment is most components for human life، but up to now، it''s real value and contribution is not specified clearly. Birds are one of the most important elements in the environment، which had already exposed by habitat destruction، increasing environmental pollution and low priority management that reduced their count in recent years. The purpose of this research was brief speech emphasizing the economic value of three species of birds in north of Iran. To achieve these purposes، two wetlands، Anzali and Gomaishan in the south coastal of the Caspian Sea، Iran، were chosen. Semi-winter census and registration numbers is performed on Total Count Procedure. To determine the economic value، market value considered and ultimately the value of the total population was derived. Annual economic value of these three species in the mentioned wetlands respectively، 4. 8 and 3. 2 billion Rials was calculated with the considerations set it with double the estimate. These numbers which are calculated only for three species can show importance of the ecosystem. While these results can be a good guide for other researchers associated with the value of wildlife، can be considered an important achievement for environmental managers to control and reduce the pollutants، habitat conservation improvement and especially regeneration areas for aquatic birds.

Recreational value of parks and recreational resources is amounts the people are willing to pay in order to use ecosystem services and recreational facilities. Quantifying the real value of these resources has a great importance for integrated management of human and environment and can be used as an effective tool for environmental policy improvement. The current study aimed to determine recreational value of Sofeh Mountain Park and estimate individual’s willingness to pay (WTP) based on contingent valuation method (CVM) and dichotomous choices (DC). Logit model was used for measuring of individual WTP. The results showed that variables including individual preservation WTP، income، education، age and the number of family members were significantly correlated with individual’s willingness to pay. The estimation of the expectancy of WTP using logit model led to 9985 Rials monthly per person.