Forecasting high-frequency excess stock returns via data analytics and machine learning

Borsa Istanbul introduced data analytics to present additional information about its market conditions. We examine whether this product can be utilized via various machine learning methods to predict intraday excess returns. Accordingly, these analytics provide significant prediction ratios above 50% with ideal profit ratios that can reach up to 33%. Among all the methods considered, XGBoost (logistic regression) performs better in predicting excess returns in the long-term analysis (short-term analysis). Results provide evidence for the benefits of both the analytics and the machine learning methods and raise further discussion on the semistrong market efficiency.     

Regulating rating agencies: A conservative behavioural change

We investigate whether the European regulatory reforms of the credit rating industry have been successful in improving the quality of financial institutions’ credit ratings. A shift to more conservative rating behaviour rather than rating quality improvement is identified, which is attributable to increased regulatory scrutiny. This change leads to a reduction in rating inflation and an increase in the number of unwarranted downgrades and false rating warnings in the post-regulatory period. A significant decrease (increase) in the informativeness of rating downgrades (upgrades) is evident. Our findings contrast with prior evidence for US corporates where reputational effects dominated.     

Shocks derived from mining windfalls and horizontal transfers: Exploring the permanent income hypothesis in Chilean municipalities from a spatial competition approach

We explore how spatial interaction affects the strategic use of municipal income when deciding between 1) an optimal long-run expenditure strategy versus 2) using the current income to finance current activities, a phenomenon known as the permanent income hypothesis. Even when this hypothesis is grounded in temporal logic, insufficient attention has been given to the impact of spatial dependence on this type of budget decision. Therefore, we present two reasons why spatial interaction adds new insight to this discussion. First, subnational governments located inside larger functional areas have lower average costs due to the population concentration, allowing for coordination between jurisdictions to achieve more power of negotiation and to potentially exploit economies of scale. Second, local government decision-making is not independent of other jurisdictions as municipalities would constantly evaluate the others’ actions regarding local tax effort, spending, and debt. While this spatial consideration remains a challenge for theoretical modeling, we offer empirical evidence to evaluate how robust the permanent income hypothesis is when geography is incorporated. Our empirical approach uses dynamic panel data with spatial dependence on debt, expenditure, and the error term. To evaluate our hypothesis, we exploit panel data from 320 Chilean municipalities between 2008 and 2020 and use two sources of income: non-matched grants via mining windfalls and horizontal fiscal transfers among cities. The evidence indicates that jurisdictions make backward-looking decisions regarding spending; that is, there are no significant differences between the short and long run. The results for debt, however, are not robust. Policy pertaining to the use of public resources should consider the spatial dependence between municipalities which should be a crucial factor in budgetary decision-making.     

不同管理处服务质量均值比较研究——以保利广州物业管理有限公司为例

在对保利广州物业管理有限公司六个管理处进行服务质量测评的过程中,我们采用多种统计方法,对不同管理处服务质量样本均值差异比较进行了假设检验,纠正了简单采用样本均值比较的错误,为物业管理服务质量测评工作提供了科学的方法。     

Diagnostic Tests for the Necessity of Weight in Regression With Survey Data

To weight or not to weight in regression analyses with survey data has been debated in the literature. The problem is essentially a tradeoff between the bias and the variance of the regression coefficient estimator. An array of diagnostic tests for informative weights have been developed. Nonetheless, studies comparing the performance of the tests, especially for finite samples, are scarce, and the theoretical equivalence of some tests has not been investigated. Focusing on the linear regression setting, we review a collection of such tests and propose enhanced versions of some of them that require an auxiliary regression model for the weight. Further, the equivalence of two popular tests is established which has not been reported before. In contrast to existing reviews with no empirical comparison, we compare the sizes and powers of the tests in simulation studies. The reviewed tests are applied to a regression analysis of the family expenditure using the data from the China Family Panel Study.     

环境规制、融资约束与企业绿色创新——来自长三角制造业的经验证据

对2013—2018年181家企业环境规制、融资约束和企业绿色创新的关系进行实证分析。研究发现：地方加强环境规制能够显著提高企业绿色创新能力，融资约束对企业绿色创新具有抑制作用；融资约束在环境规制与企业绿色创新关系中起到显著的负向调节效应，削弱了环境规制对企业绿色创新的正向影响。异质性分析表明：融资约束对国有企业绿色创新具有抑制作用；而对于非国有企业具有正向激励作用，但调节效应不再显著。根据研究结论，利用利益相关者理论，分别从政府、金融机构、企业自身角度提出相关的对策。