On a new positive dependence concept based on the conditional mean inactivity time order

In this paper, we introduce a new positive dependence concept between two non negative random variables which is related to a conditional version of the mean inactivity time order. A number of properties and relationship between the new notion and the concept of positive likelihood ratio dependence (PLRD) is discussed. Some results in terms of proposed notions for the Archimedean family of copulas are provided.     

安徽省P2P网贷平台运营现状及发展对策研究

文章立足于安徽省P2P网贷平台的发展现状,通过对比分析,发现安徽省P2P平台无论是数量还是交易规模较国内发达地区还存在较大差距,同时平台跑路、提现困难问题突出。为此,从政府加强P2P行业监管、发挥行业自律的作用、差异化市场定位和提升从业人员素质四个方面来为发展安徽省P2P网贷平台提供对策。     

Stein-like 2SLS estimator

ABSTRACT

Maasoumi (1978 Maasoumi, E. (1978). A modified Stein-like estimator for the reduced form coefficients of simultaneous equations. Econometrica 46:695–703.[Crossref], [Web of Science ®] , [Google Scholar]) proposed a Stein-like estimator for simultaneous equations and showed that his Stein shrinkage estimator has bounded finite sample risk, unlike the three-stage least square estimator. We revisit his proposal by investigating Stein-like shrinkage in the context of two-stage least square (2SLS) estimation of a structural parameter. Our estimator follows Maasoumi (1978 Maasoumi, E. (1978). A modified Stein-like estimator for the reduced form coefficients of simultaneous equations. Econometrica 46:695–703.[Crossref], [Web of Science ®] , [Google Scholar]) in taking a weighted average of the 2SLS and ordinary least square estimators, with the weight depending inversely on the Hausman (1978 Hausman, J. A. (1978). Specification tests in econometrics. Econometrica 46:1251–1271.[Crossref], [Web of Science ®] , [Google Scholar]) statistic for exogeneity. Using a local-to-exogenous asymptotic theory, we derive the asymptotic distribution of the Stein estimator and calculate its asymptotic risk. We find that if the number of endogenous variables exceeds 2, then the shrinkage estimator has strictly smaller risk than the 2SLS estimator, extending the classic result of James and Stein (1961 James W, ., Stein, C. M. (1961). Estimation with quadratic loss. Proceedings of the Fourth Berkeley Symposium on Mathematical Statistics and Probability 1:361–380. [Google Scholar]). In a simple simulation experiment, we show that the shrinkage estimator has substantially reduced finite sample median squared error relative to the standard 2SLS estimator.     

我国 P2P 网络借贷平台中的法律问题

作为一种金融创新,P2 P网络借贷平台有"信息中介型"和"资金运作型"两种经营模式.前者属于单纯的中介模式,网络借贷经营活动主要体现了居间合同和借款合同的法律属性;后者是网贷平台通过平台自身担保、风险储备金、第三方机构担保这三种方式来保障出借人资金安全,吸引更多的人参与网络借贷.P2 P网贷平台的法律风险主要有交易资金缺乏监管,形成资金池;经营方式中的"大单模式"、平台自身担保存在风险;运营信息披露不真实、不充分.要防范这些风险的发生,网贷平台必须建立独立的中间账户,实行资金第三方托管制度;实施小额分散贷款,限制网贷最高金额;加强风险控制,禁止网贷平台自身提供担保;加大借款人信用评估,完善个人征信体系.     

An extension of Horvitz–Thompson estimator used in adaptive cluster sampling to continuous universe

In this paper, an extension of Horvitz–Thompson estimator used in adaptive cluster sampling to continuous universe is developed. Main new results are presented in theorems. The primary notions of discrete population are transferred to continuous population. First and second order inclusion probabilities for networks are delivered. Horvitz–Thompson estimator for adaptive cluster sampling in continuous universe is constructed. The unbiasedness of the estimator is proven. Variance and unbiased variance estimator are delivered. Finally, the theory is illustrated with an example.     

Target setting for indirect processes: a new hybrid method for the continuous improvement management of indirect processes

Indirect processes are increasingly contributing to the total cost of production in highly competitive and technology-intensive industries. Unfortunately, they are less assessable than direct processes due to the complex organisational management structure. Therefore, companies seeking to make improvements in indirect areas need decision support methods to indicate which indirect process needs to be improved and to what extent. To facilitate this task, the target setting for indirect processes (TSIP) method has been developed following the constructive research approach. TSIP is a combination of process modelling, the analytic network process, activity-based management from managerial accounting research and the value control chart from target costing research in a kaizen budgeting framework. This new hybrid method is developed and validated in cooperation with a global first-tier automotive supplier.     

Does schooling protect sexual health? The association between three measures of education and STIs among adolescents in Malawi

While multiple studies have documented shifting educational gradients in HIV prevalence, less attention has been given to the effect of school participation and academic skills on infection during adolescence. Using the Malawi Schooling and Adolescent Study, a longitudinal survey that followed 2,649 young people aged 14–17 at baseline from 2007 to 2013, we estimate the effect of three education variables: school enrolment, grade attainment, and academic skills—numeracy and Chichewa literacy—on herpes simplex virus type 2 (HSV-2) and HIV incidence using interval-censored survival analysis. We find that grade attainment is significantly associated with lower rates of both HSV-2 and HIV among girls, and is negatively associated with HSV-2 but not HIV among boys. School enrolment and academic skills are not significantly associated with sexually transmitted infections (STIs) for boys or girls in our final models. Efforts to encourage school progression in high-prevalence settings in sub-Saharan Africa could well reduce, or at least postpone, acquisition of STIs.     

The benefits of joint and separate financial management of couples

Financial management differs across households with consequences for financial outcomes and well-being of partners in households. A large-sample study has been performed, investigating the relationship between financial management of households and the occurrence of financial problems. To our knowledge, this is the first study on this relationship. Data from both partners was collected on having joint and separate bank accounts, on financial decision making, on drivers of financial management, and on financial outcomes. Based on the data, four financial management styles were derived: syncratic/joint, male-dominant, female-dominant, and autonomous financial management. In the syncratic style, partners have a joint bank account and take most financial decisions together. In the male/female-dominant styles, one partner (husband or wife) takes the main financial decisions. In the autonomous style, both partners have their own bank accounts and make their own decisions. As a conclusion, we find that syncratic financial management and having a joint instead of a separate bank account correlates with fewer financial problems, as compared with male-dominant money management and having separate bank accounts. Deciding together as partners is beneficial for the quality of financial management and for avoiding financial problems.     

Estimation for varying coefficient partially nonlinear models with distorted measurement errors

In this paper, we propose a new varying coefficient partially nonlinear model where both the response and predictors are not directly observed, but are observed by unknown distorting functions of a commonly observable covariate. Because of the complexity of the model, existing estimation methods cannot be directly employed. For this, we propose using an efficient nonparametric regression to estimate the unknown distortion functions concerning the covariates and response on the distorting variable, and further, we obtain the profile nonlinear least squares estimators for the parameters and the coefficient functions using the calibrated variables. Furthermore, we establish the asymptotic properties of the resulting estimators. To illustrate our proposed methodology, we carry out some simulated and real examples.     

Principal weighted logistic regression for sufficient dimension reduction in binary classification

Sufficient dimension reduction (SDR) is a popular supervised machine learning technique that reduces the predictor dimension and facilitates subsequent data analysis in practice. In this article, we propose principal weighted logistic regression (PWLR), an efficient SDR method in binary classification where inverse-regression-based SDR methods often suffer. We first develop linear PWLR for linear SDR and study its asymptotic properties. We then extend it to nonlinear SDR and propose the kernel PWLR. Evaluations with both simulated and real data show the promising performance of the PWLR for SDR in binary classification.