出口供应安全及基础设施影响下的天然气进出口博弈

鉴于出口国时常出现天然气出口供应安全问题，进口国因基础设施滞后引发的天然气供需矛盾，考虑出口供应安全、基础设施与需求量三者之间的相互影响，文章构建了进出口两国之间的动态博弈模型。运用最优控制等理论，求得了双方的均衡策略及效用。结果表明，天然气出口价格越高，使得进口国的天然气销售价格越高及其对基础设施投入越少；出口国为保障出口供应安全付出的努力与天然气出口价格之间呈倒“U”型关系；与天然气寡头竞争市场相比，出口垄断市场的天然气出口价格、出口供应安全、基础设施存量以及出口国效用更高，进口国效用更低；在寡头竞争市场，与合作方式相比，两国在议价下的天然气出口价格、出口供应安全、基础设施存量以及出口国效用更高，进口国效用更低。

Natural Gas Importing and Exporting Strategy under Influence of Supply Security Abroad and Domestic Infrastructure

In recent years,exporting countries such as Russia often suffer from disruptions in natural gas export supply due to natural disasters, economic, political and military factors. Once the natural gas export supply security problems occur, not only the importing countries suffer enormous economic losses, the interests of the exporting countries will also be severely damaged. So gas export supply security is an important aspect that should be highly valued by the exporting countries. On the other hand, gas import for some countries such as China has risen steadily during this period. In the process of rapid development of natural gas market, the natural gas infrastructure has been improved significantly, but it is still a key factor which restricts its gas consumption. Therefore, importing countries should pay more attention to the construction of natural gas infrastructure. In this context, a dynamic game problem characterized by natural gas importing and exporting countries with conflicted interests is studied, with focus mainly on a perspective of supply security abroad and domestic infrastructure.Specifically, in the first section of this paper, the main players, objective functions and strategy sets are discussed, and a dynamic game model is established to reflect the importing country's economic objective and the exporting country's supply stability and economic consideration. The second section uses the optimal control theory to study the optimal strategy of the optimal sales price and infrastructure investment in the importing country, and the optimal production strategy for the exporting country. The third section mainly analyzes the optimal export price under different market scenarios. Results show that, a higher export price will lead to a higher domestic sales price and a less infrastructure investment. The exporting countries' effort has a form of inverted "U" in relation to export price. Export prices, export supply security, infrastructure stock and utility of the exporting country are higher, and utility of the importing country is lower in an exporting monopolistic market than in a monopolistic market. For an exporting monopolistic market, export prices, export supply security, infrastructure stock and utility of the exporting country are higher, and utility of the importing country is lower in the case of negotiation than in the case of cooperation.