Urbanization agglomeration that is named Jacobs EXTERNALITIES, refers to the role of economic diversification in urban. Localization agglomeration, Marshal-Arrow-Romer (MAR) EXTERNALITIES, is related to the concentration of firms activated in a special industry within a specified place. The purpose of this research is to explore the impact of different types of agglomeration economies on employment growth for provinces of Iran in 1996-2006. Empirical results demonstrate a U-shaped relationship between specialization and urban growth We find a positive impact of JACOBS'S EXTERNALITIES on employment growth in provinces of Iran.

One of the arguments in justifying the necessity of education is its EXTERNALITIES. A case of these external outcomes appears as improvement of environmental quality or prohibition of natural destruction that benefits all of people. In other words, it is claimed that education leads to the better atmosphere of life and less hazardous environment. The main purpose of this paper is to investigate that idea, with special reference to preservation of forests, and then to provide some evidence. The used method is regression analysis on the basis of documented data sources. Accordingly, a sample including 158 countries throughout the world is used which classified to three sub-samples. The data are related to 2010. Results suggest that enrolment in secondary and higher education in low income countries and enrolment in secondary education in middle income countries have negative impact on deforestation. Therefore, it can be said that education is one of the determinants in lowering deforestation in worldwide.

This study investigates externality costs of groundwater overexploitation to produce pistachio on pistachio market of Iran. Domestic demand functions, export demands and supply of pistachio with and without externality costs of groundwater overexploitation were estimated for the period 1980-2011. Then, the effects of externality costs on key variables of market and welfare were investigated applying mathematical programming model. The results showed that externality costs of groundwater overexploitation to produce pistachio lead to a shift of the supply curve is upward and to the left. Therefore, the amount of current supply of pistachios without considering externality costs is larger than socially efficient level. On the other hand, the market price is lower than the socially efficient price. Accordingly, with considering externality costs the market price variables increased and the amount of domestic demand, export demands and supply decreased. Finally, with considering total externality costs the consumer and producer welfare, export income and total welfare or social welfare decreased. Certainly considering externality costs prevents groundwater overexploitation and the present value of the benefits of this action will increase in the long run.

Internet markets like the application of the other Information Technologies result in decreasing cost and increasing efficiency. Sellers have lower costs and higher profits and also consumers with more information can experience better choices and cheaper shopping. Therefore, it seems that the growth of markets on the internet is as an indicator of improved competition. Nevertheless there are specific characteristics of the internet that could increase monopoly in internet markets. In this paper the presence of monopoly in internet markets is studied from different aspects with emphasis on network EXTERNALITIES. The results show that the presence of network EXTERNALITIES produces monopolies in internet markets. Also competition in internet markets involves R&D-races aimed at capturing market share through innovation or retaining market leadership by creating new innovations. It could be concluded that monopolistic market structure in internet market (in contrast to traditional monopoly markets) does not decrease consumer surplus, rather consumer surplus will increase through creation of innovations

Ship exhaust emission inventories and their associated EXTERNALITIES constitute valuable information resources towards policy making and management of the influence exerted by shipping on air quality. To this extent, the container terminal at the Greek Port of Piraeus by virtue of its shipping significance and its urbanised character was selected in order to provide an estimation of the emissions produced by the ship activity within the terminal and to monetarise their adverse effects upon the environment and the local population in particular. With reference to the year 2006, the relevant annual emission inventory generated during in-port ship manoeuvring and at berth was found to be equal to 16, 104 tons, divided into 294, 264, 15, 504, 16.5 and 26.4 tons of NOx, SO2, CO2, HC and PM, respectively. The overall damage of these emissions was estimated to be around 7.5 million euro, comprised by 2.15, 3.35, 0.6, 0.003 and 1.35 million euro of NOx, SO2, CO2, HC and PM, respectively. The findings of this work, along with similar studies recently conducted in neighbouring locations, provide useful information towards the completion of a detailed and accurate picture of ship exhaust emissions and their EXTERNALITIES within the region of the eastern Mediterranean.

The adherents of new institutionalism have considered exchange costs as the factor behind the formation of EXTERNALITIES, and with an emphasis on the bilateral nature of EXTERNALITIES, have criticized the traditional approach to economy. Some argue that institutionalism can have implications for Islamic economics, especially in terms of the method of analyzing economic behaviors and phenomena. Using an "analytical" method, this research examines the implication of the "new institutional approach for dealing with EXTERNALITIES" in Islamic economics. The results of the research indicate that the above-mentioned approach does not have obvious implications for Islamic economics at least for three reasons: 1. Contrary to the institutional view, exchange costs is not the only factor in the occurrence of EXTERNALITIES in Islamic economics; 2. In the face of EXTERNALITIES in Islamic economics, in addition to maximizing the entire product (which is the goal of the new institutionalists), other goals, such as pursuit of the interests of society are also considered; 3. New institutionalists, with the criterion of economic cost-benefit, make a special decision in each case; While in Islamic economics, firstly, the only criterion for decision-making is not economic cost-benefit; secondly, sometimes the strategy for coping with EXTERNALITIES is determined and unchangeable.

Environmental cost–benefit analysis is applied for the evaluation of renewable energy projects. Since some benefits and costs do not have market values, it is imperative to apply economic valuation techniques in order to estimate them. The need for investment in renewable energies is apparent, considering the earth’s finite resources and their fast depletion. Fossil fuels draw on finite resources, which eventually dwindle, become too expensive or too environmentally detrimental to retrieve. It is of considerable interest to policy makers to know if individuals are willing to pay more for renewable energies rather than for fossil fuel energy.Choice experiment method is applied in the valuation of non-market goods. This paper estimates the willingness to pay for a hypothetical program that promotes the utilization of renewable energies. Using the choice experiment method, we estimate preferences of respondents for electricity produced using renewable energy resources. Responses to the choice questions show that our respondents favor policies promoting the utilization of renewable energies and strongly approve of the reduction of pollution caused by thermal power plants.Our results, therefore, suggest that consumers are willing to pay a higher price for electricity in order to internalize the external costs of energy security, climate change, and air pollution caused by thermal power plants. On the other hand, these results show that as incomes increase willingness to pay increases, while the willingness to pay is negatively associated with age and education has no significant effect on WTP.

Natural resources are valuable capitals for all nations. Rangelands as the most extensive natural ecosystems in Iran provide numerous services, including fodder production and red meat supply, soil conservation and water regulation. Although uncontrolled exploitation of these resources has imposed much pressure and caused many losses within the ecosystems. Impacts of overutilization of nomadic livestock on Semirom rangelands from runoff control perspective has been the core objective of this study. Considering the utilization conditions, vegetation cover was measured within the vegetation types before and after livestock grazing during 2013 grazing season. Curve Number method was selected to evaluate the runoffs originating from rainfalls with different return periods before and after livestock grazing and the difference was considered as the grazing impact. This externality was valuated using replacement cost method. Results showed that utilization pressure is extremely more than grazing capacity which has distorted water regulation function of the rangelands, e.g. it has increased the runoff volume from a rainfall with 2-year return period from 1660884 to 2600487 m3.In other words, it has diminished the potential of rangelands in controlling water runoffs.Economically speaking, the external damage to water regulation function of rangelands was calculated at the rate of 25391 million Rial/year. This information on the EXTERNALITIES of nomadic livestock will provide the useful basis for economic appraisal of the utilization process and adjustment or rectification of economic activities which entail social costs on their way towards private profits.