标题： 螺旋式迈向市场完备性和金融不稳定 显示英文标题

标题： Spiraling toward market completeness and financial instability

摘要： 我研究了一个大型随机经济的极限情况，其中一组消费者投资由银行设计的金融工具，以优化他们的未来消费。 这一分析表明，即使在完全竞争的理想情况下，所有市场参与者都能获得完整信息，随着市场接近完善且交易成本消失，均衡状态会显现出对市场不完善的显著脆弱性（或敏感性）。 交易成本的降低源于金融机构利用交易工具对冲其他工具。 这导致了银行间市场的交易量在完全市场极限下出现分歧。 这些结果表明，金融工具的激增加剧了市场不完善的影响，呼吁将市场视为相互作用系统的理论。 从另一个角度看，为了防止不良影响升级，随着市场复杂性的扩大，市场可能需要更加明显的制度结构。 显示英文摘要

摘要： I study the limit of a large random economy, where a set of consumers invests in financial instruments engineered by banks, in order to optimize their future consumption. This exercise shows that, even in the ideal case of perfect competition, where full information is available to all market participants, the equilibrium develops a marked vulnerability (or susceptibility) to market imperfections, as markets approach completeness and transaction costs vanish. The decrease in transaction costs arises because financial institutions exploit trading instruments to hedge other instruments. This entails trading volumes in the interbank market which diverge in the limit of complete markets. These results suggest that the proliferation of financial instruments exacerbates the effects of market imperfections, calling for theories of market as interacting systems. From a different perspective, in order to prevent an escalation of perverse effects, markets may necessitate institutional structures which are more and more conspicuous as their complexity expands.