中文摘要：

金砖国家基础设施建设存在巨大融资缺口，其庞大的外汇储备缺乏盈利渠道，成员国各自封闭式管理成本高昂。基础设施投资需求和外汇储备盈利需求的耦合，成为设立金砖国家开发银行的现实动因。金砖国家经济的波动协动性和比较优势，使成员国问的合作利益得以优化。基于协动性的博弈模型分析，从逻辑上可推演出金砖国家合作的必要性。与其他合作方式相比，网络虚拟性使金融合作在短期内具有高效益。金砖国家经济的发展与稳定之间的抱互性关系，为其设立开发银行奠定逻辑基础。

英文摘要：

The BRICS basic infrastructure suffers from a huge financing gap, but their massive foreign exchange reserves lack profitable outlets and member states＇ self-contained management costs are extremely high. The coincidence of the need for basic infrastructure investment and the need for profitable foreign exchange reserves are the immediate reasons for setting up the BRICS Development Bank. Comparative advantage and the co-movement of fluctuations in the BRICS member states optimize their cooperative interests. A co- movement game model analysis enables us to deduce the logical necessity for cooperation among the BRICS. Compared with other patterns of cooperation, virtual networks enable this financial cooperation to yield benefits in a short timeframe. The mutually supportive relationship between development and stability in the BRICS economies provides a solid rationale for the establishment of the New Development Bank.