| 1. Introduction Although, sustainable supply chain is currently of interest to many researchers, the sustainability has not been paid much attention in Petroleum Supply Chain (PSC). According to the Carter and Rogers’ sustainability definition “the strategic, transparent integration and achievement of an organization’s social, environmental, and economic goals is the systematic coordination of key inter-organizational business processes for improving the long term economic performance of the individual company and its supply chain” (Carter and Rogers, 2008). Considering the following aims at the same time, sustainability is an inalienable part of the petroleum supply chain: Many environmental regulations have been enacted by the governments to reduce the environmental and pollution effects. Maximizing the profit of whole chain such as the other supply chains. Most of the governments enforce the stakeholders by enacting appropriate regulations to increase the created job in the chain. Beside of the sustainability, the competition is another important factor in the PSC. Because, different parts of a petroleum supply chain are controlled by different stakeholders and stakeholders’ attempt to maximize their profits emerges competition. This can be defined as a complete competition which is not enough to analyze the developing countries PSC, and we need to take into account the other ongoing factors. In the developing countries, PSC is controlled by governments, which spend millions of dollars on refined petroleum products such as gasoline, diesel, etc. In these countries, large volume of subsidies causes artificial low prices and the economic and financial problems, this in turn causes fading out of optimization of economic consumption and market competitions (Cheon et al., 2013). Considering the economic and financial problems, countries take corrective measures such as gradual reduction of subsidies to ultimately complete elimination and inclusion of private sector in the petroleum supply chain. Therefore, like in the developed countries, there are various stakeholders in the petroleum supply chain and the main challenge is between the supply chains of the government and private sector to determine their price and demand balance. Hence, three other factors that play important role in optimizing of the PSC are: i) rate of the reduction in subsidies in different periods. ii) Government’s subsidized price. iii) Government’s unsubsidized price. As mentioned before, the subsidies will be gradually diminished in each year with respect to government planning. Thus, the prices (subsidized and unsubsidized) are adjusted by the government and the private sectors for each of the products as well as their demand based on the amounts of subsidies i.e. determined and paid by the government every year. In other words, the government and private supply chains compete to determine the adjusted prices and demands which is referred as a competitive chain. This competition can be non-cooperative. Despite the significance of pricing in PSC, the pricing of petroleum products by considering competition between private sectors and government chains has hardly been dealt with in the literature. Just Moradi Nasab et al. (2016) proposes an integrated economic model (IEM) of fossil fuel energy planning for government and private sectors. In their study, there is competition between refineries within the refinery level, between distribution centers (DCs) within the distribution center level, and between refineries and DCs. Under these conditions, part of the refineries and DCs are under the control of government and the remainder are controlled by the private sectors. whereas, the non-cooperative competition between the private sectors and government chains have been considered in this study |