独家交易对平台内经营者销量的影响研究——来自互联网外卖平台的实证证据

互联网平台独家交易行为越来越受到反垄断部门的重视，而其经济效应较为复杂，在业界尤其是学界尚存争议。本文首先基于Hotelling模型分析独家交易前后用户的归属变化，并考虑平台赋能和品牌异质性对独家后商家销量的影响，分解其作用机制。再基于2019年西部某重要城市互联网外卖平台的数据进行实证检验和分析，使用倾向得分匹配—双重差分法评估了外卖平台G独家交易对平台内经营者销量影响的净效应。结果表明，独家交易通过渠道效应降低了商家的总销量，而没有出现显著的能提高商家销量的用户转移效应。因此，平台并未在销量提升上有效赋能独家交易的商家。异质性分析发现，品牌商家独家后销量受到的负面影响高于非品牌商家。本文可以为反垄断相关执法提供参考和支持。     

Topological properties of reconstructed credit networks and banking systemic risk

Financial bipartite networks provide channels for contagion risks and their topological properties determine financial stability. We enrich the bipartite network reconstruction methods proposed by Ramadiah et al. (2020) and extend them to the Chinese banking system. By comparing the reproducibility of the real credit market and the corresponding systemic risk, the impact of topological properties for different reconstructed bipartite networks on financial stability is analyzed. The empirical evidence shows that network reconstruction methods based on maximum entropy ensembles capture more properties in the real credit network. It also highlights that the different systemic risk level is mainly contributed by the topological properties based on common exposures. These analyses for topological properties provide regulatory insights for systemic risk prevention. It shows that reducing credit similarity across banks while increasing credit diversification in different sectors helps to control systemic risk. The results imply the possibility of increasing financial stability through the macro-regulation of the credit market structure.     

一种需求不确定下的回购策略设计

基于促销努力影响需求、零售商不允许缺货且可以二次订货的情况,本文建立了由一个供应商和一个零售商组成的二级供应链回购契约模型,论证了无论是单纯回购策略还是回购策略下努力成本共担都不能实现供应链的协调,并引入奖励与惩罚策略来达到协调作用。最后,通过算例对模型进行了分析。     

Inefficient liquidity creation

We present a model in which intermediaries create liquidity by issuing safe debt. Two types of intermediaries emerge: Traditional banks that create liquidity by issuing equity and holding assets to maturity, and market-based intermediaries that create liquidity by selling assets in fire sales in downturns. We show that the reliance on market-based intermediation is necessarily too high, but liquidity creation is not. It can also be too low as the endogenous fire-sale risk can push liquidity creation below its optimum. We argue that standard capital or liquidity regulation are ineffective, and optimal macroprudential regulation should instead target market-based intermediation.     

Menu simplification for portfolio selection under short-sales constraints

We introduce a risk-reduction-based procedure to identify a subset of funds with a resulting opportunity set that is at least as good as the original menu when short-sales are imposed. Relying on Wald tests for mean-variance spanning, we show that the better results for the subset can be explained by a higher concentration of covariance entries between its assets, ultimately leading to smaller Frobenius norms of the associated matrices. With data on US-defined contribution plans, where participants have limited financial literacy, tend to be overwhelmed and prefer to make decisions among fewer choices, we obtain a 75% average reduction.     

Mitigating fire sales with a central clearing counterparty

Theoretically, one rationale for central clearing counterparties is the mitigation of inefficiencies associated with distressed asset sales. With novel archival data, I empirically study the first event in economic history during which a CCP successfully played this role: the global wool crisis of 1900. In the leading wool futures market in France, an inefficient equilibrium with fire sales and cascading defaults could be avoided due to price support provided by surviving CCP members. Cooperation to achieve price support–which is nowadays the main element of CCP auctions–could arise due to family relationships and cultural proximity between traders.     

How does the insurer's mobile application sales strategy perform?

While the impact of an Internet-based sales strategy on sales performance has been well studied, there is little academic research that examines the impact of a mobile application (MA) sales strategy on the sales performance of insurers. Using a unique data set for term life insurance policies from a Chinese life insurer, we study the impact of implementing this strategy on insurance purchases. We find a significant growth in the insurance purchase quantity and somewhat lower growth in premiums received from new policies. This paper determines that this is due to improved channel accessibility and the cost reduction of the MA channel. Although sales of traditional distribution channels are cannibalized in the short term by the MA distribution strategy, this substitution effect does not persist in the long run. In addition, we find that this strategy reduces impulsive purchases.     

System-Wide Runs and Financial Collapse

This paper presents a model in which small shocks to asset values can trigger system-wide runs. When lenders cannot distinguish which financial institutions have suffered losses after an adverse shock to asset values, healthier institutions can differentiate themselves from weaker firms by offering to borrow less at more favorable prices. However, to successfully separate, the healthy institutions must liquidate a fraction of their portfolio causing asset fire sales. Fire sales worsen the balance sheet integrity of the firms and, if too severe, this leads to a complete collapse of the financial system: a system-wide run.     

基于主题模型的网络流通渠道服务质量分析与评价体系研究

通过构建网络流通渠道服务质量评价体系,为网购服务质量评价研究提供借鉴,为渠道掌握用户服务需求,提升自身服务能力提供帮助。通过词频统计与可视化分析手段,描绘不同网络流通渠道的服务差异与用户群体特征。利用主题模型提取不同情感倾向下的评论主题,得到用户对渠道服务的感知维度,构建指标体系。最终获得基于文本挖掘的不同网络销售渠道服务特征与用户画像,以及不同于传统指标的全新渠道服务质量评价体系,并且通过测度结果,展现了三类流通渠道服务水平的差异。     

商业模式创新与审计收费——基于线上销售的视角

考察企业线上销售这一商业模式创新对审计收费的影响，基于2009—2020年我国全部A股上市公司的年报数据，利用Python语言构建企业开展线上销售的度量指标，实证研究发现,企业开展线上销售会使得审计收费显著增加,该结论在经过一系列稳健性检验后仍然成立。从机制检验结果来看，线上销售增加了审计风险，导致审计师采取更多的应对措施，从而提高了审计收费。异质性分析结果表明，“四大”事务所、具有行业专长以及具有较高信息技术水平的审计师审计会削弱线上销售对审计收费的正向影响。总之，厘清了线上销售这一商业模式创新对上市公司审计收费的影响及作用机制，加深了关于商业模式创新对企业经营及审计行为影响的认识，同时也为推动审计行业转型发展提供了有益启示。