The Hurst exponent is a key parameter for characterizing the long memory of high-frequency time series. However, traditional estimators often exhibit systematic biases due to the influence of high-frequency endogenous noise and low-frequency trend shifts. Theoretical derivations show that endogenous noise contemporaneously correlated with the latent signal possesses a spectral density in the first-differenced series that is asymptotically equivalent to a squared sine functional form. Accordingly, the proposed estimator incorporates a corresponding spectral density component to fit the high-frequency error. Simultaneously, the model introduces a SCAD penalty term to control the low-frequency spectral divergence caused by structural breaks, thereby mitigating spurious long memory in parameter estimation. Monte Carlo simulations demonstrate that the Penalized Mixture Whittle estimator yields smaller finite-sample biases and root mean square errors in scenarios involving both trend disturbances and endogenous noise. Empirical analysis shows that the estimates obtained using this method are robust to changes in sampling frequency. In further volatility forecasting experiments on commodity futures, the linear forecasting model constructed based on the parameter set achieves higher prediction accuracy than benchmark models such as HAR, as confirmed by the Diebold-Mariano test. This paper provides an effective econometric tool for high-frequency data inference in the presence of composite statistical disturbances.

耐心资本作为一种强调长期价值创造的资本形态，对于企业可持续发展及金融市场稳定运行具有重要意义，但其难以自发形成，需要外部激励与内部治理的共同培育。基于权力—收益矩阵，本文引入了耐心资本的主要来源——股东，构建了股东权力—收益矩阵分析框架，旨在从股东权力和股东收益视角进一步探讨耐心资本的形成机制。选取2014—2023年沪深A股上市公司为样本，采用固定效应回归检验主效应，结果发现，股东权力与股东收益均显著正向促进耐心资本形成，在通过滞后一期、替换被解释变量、调整样本期、增加固定效应以及工具变量2SLS缓解潜在内生性后，结论依然具有稳健性；异质性分析显示，在制造业、获得标准审计意见、上一年未亏损、南方地区以及非重污染企业中，上述效应更为显著；中介效应检验表明，股东权力主要通过缓解融资约束促进耐心资本形成，股东收益主要通过降低融资成本促进耐心资本形成；调节效应检验证明，内部控制质量均能够正向强化股东权力与股东收益对耐心资本的促进作用。研究结论回答了耐心资本何以形成的问题，为通过提升公司股东治理质量、壮大耐心资本供给提供了理论依据与实践启示。

I study whether workplace smoking bans change how bond investors assess firm risk. Using staggered state adoption across U.S.\ states from 2002 to 2012 and a heterogeneity-robust difference-in-differences design, I find that smoking bans increase six-month cumulative abnormal bond returns by about 90 basis points. The average effect is only the starting point: the response is much larger for speculative-grade issuers and firms with low interest coverage, indicating that investors reprice the policy where downside operating risk matters most for debt values. Mechanism tests point most clearly to improved operating performance and lower worker turnover, while broader financial-constraint, liquidity, and duration channels remain close to zero. Alternative estimators, placebo diagnostics, and geographic spillover checks all support the interpretation that workplace smoking bans trigger targeted credit-risk reassessment rather than a generic regional shock. My findings connect public-health regulation to capital-market outcomes and show how non-financial policy shocks can reveal economically meaningful information about corporate credit risk.

大豆是我国重要的粮油兼用作物，在保障国家粮食安全方面具有战略意义。山东省作为我国大豆主产区之一，面临着种植面积缩减、种植效益偏低、生产成本上升等多重挑战。收入保险在保障农民利益，助力农业蓬勃发展中发挥着不可替代的作用，且随着农业保险的高质量发展，其一定会成为未来农业保险发展的重点。同时，农业生产具有显著的地域差异性，统一费率的农业保险产品难以满足不同地区的实际需求。故本研究以山东省大豆为研究对象，基于2005-2023年的历史数据，构建多维风险区划指标体系，采用系统聚类法将山东省16个地级市划分为低、中低、中高、高风险四个等级。在收入保险定价方面，采用Copula函数刻画单产与价格的相关关系，并创新性地构建双层定价模型（加入村级层面产量波动）捕捉空间异质性风险，基于实际大豆保险赔付率进行参数校准，定价也依照保险实务采用相对免赔机制，比较不同免赔率下的费率变化。研究发现，村级层面的空间异质性风险显著，单层模型严重低估真实风险，双层效应在高风险区尤为明显。本研究对山东省大豆收入保险实际定价的改进具有重要参考价值。

This paper investigates how government fiscal constraints transmit to the private sector through procurement. We exploit three rounds of VAT rate cuts in China (2017–2019) as exogenous shocks to local government revenues. Combining city-level fiscal pressure measures with 9,189 procurement contracts from A-share listed firms, we construct a firm-year exposure index weighted by procurement volumes across cities. We find that exposure to fiscally stressed government buyers significantly depresses firm valuation: a one-standard-deviation increase reduces Tobin's Q and price-to-sales ratios by 5.3% and 4.3%, respectively. This effect concentrates among private firms, those lacking industrial policy support, and firms with lower rent-seeking expenditures—precisely those with weaker bargaining power against government counterparties. Beyond valuation, such exposure leads to a subsequent deterioration in firm fundamentals, characterized by tightened liquidity constraints, reduced investment and financing, and worse information disclosure over a three-year horizon. Land finance partially buffers these effects. Our findings highlight an unintended micro-level consequence of macro fiscal policy: expansionary tax cuts designed to stimulate the private sector may inadvertently harm firms by weakening the government's capacity to fulfill procurement payments.

This paper studies how air pollution shapes offline cashless spending in China. Using monthly transactions from 118,698 merchants in 332 cities from 2019 to 2023, we find that higher pollution raises cashless spending. Instrumental variable and regression discontinuity designs confirm a causal effect. The increase comes mainly from more frequent but smaller purchases and greater participation by new customers. Spending also rebalances from postponable durables toward high-frequency, proximity-based categories, while durables respond little. These results uncover a behavioral channel whereby poor air quality shifts the margins and the composition of offline cashless commerce.

在我国当前低利率环境下，债券收益率持续下行，多元化资产配置的战略意义愈发凸显。本文基于桥水全天候理念，构建了适用于中国投资者的宏观因子增广Black-Litterman（ABL）模型，将宏观信号嵌入传统Black-Litterman（BL）模型的观点矩阵，同时整合风险平价先验基准，有效缓解了传统BL模型参数敏感性高及经济解释性不足问题。基于2012-2024年股债商汇四大类14项资产的回测表明，ABL模型实现了17.7%的年化收益和0.66的夏普率，优于传统BL模型及其他常用基准，且在波动率和最大回撤等风控维度更为稳健。ABL模型为资产配置提供了兼具理论创新与实践价值的参考方案。

可转债是上市公司重要的融资工具，其强制赎回条款在实践中可能被上市公司利用，通过操纵股价满足强制赎回条件，以便加速转股进程。基于2006-2025年中国A股市场数据，本文分析了可转债强制赎回背景下的股价异动现象。研究发现：在强制赎回条件触发的关键窗口期，正股价格出现显著异常拉升，强制赎回公告后则迅速反转，呈现“拉高达标”的“倒V”型反转特征；面临较高偿债压力和融资成本的发行人，更倾向于通过市场操纵推动股价达到强赎条件；微观交易数据显示，临近强赎节点时，市场买卖失衡、知情交易增多及大额交易增加，验证了主力资金通过短期内大量买入推升股价的操纵机制。本文揭示了可转债强制赎回条款可能诱发的道德风险，为完善市场制度设计和保护中小投资者权益提供了实证依据。

This study examines how global turbulence factors shape volatility spillovers among emerging stock markets through the lens of risk cycles. We find that emerging market connectedness exhibits clear regime heterogeneity across risk cycles, while also preserving several persistent structural patterns. Specifically, trade policy uncertainty (TPU) and economic policy uncertainty (EPU) serve the dominant drivers during risk outbreak and risk accumulation periods, respectively. Meanwhile, sustainability uncertainty (ESGUI) consistently plays a leading driver role in both regimes, while physical climate risk plays a comparatively limited role. Furthermore, the effects of these core turbulence factors are nonlinear and threshold-dependent, highlighting the importance of accounting for risk cycle heterogeneity and nonlinear dynamics when assessing emerging market risk transmission.

This study investigates the role of contextual cues in memory-based decision-making within high-stakestrading environments. Using trade records from a large Chinese brokerage firm and a novel dataset on COVID-19 quarantines, we find that quarantine periods trigger the recall of previously traded stocks, increasing the likelihood of subsequent orders for those stocks. The observed patterns align more closely with similarity-based recall than with alternative channels. Welfare analysis reveals that these memory-induced trades lead to an annualized loss of approximately 70 percentage points for the representative investor’s portfolio. We also find evidence at the market level: when the geographical distribution of quarantine risks is recalled, the probability of recalling the cross-sectional stock return-volume distribution from the same day increases by 1.6 percentage points. This study provides causal evidence from a real-world setting for memory-based theories, particularly similarity-based recall, and highlights a novel channel through which COVID-19 policies affect financial markets.