The effect of a Durbin–Watson pretest on confidence intervals in regression

Consider a linear regression model and suppose that our aim is to find a confidence interval for a specified linear combination of the regression parameters. In practice, it is common to perform a Durbin–Watson pretest of the null hypothesis of zero first‐order autocorrelation of the random errors against the alternative hypothesis of positive first‐order autocorrelation. If this null hypothesis is accepted then the confidence interval centered on the ordinary least squares estimator is used; otherwise the confidence interval centered on the feasible generalized least squares estimator is used. For any given design matrix and parameter of interest, we compare the confidence interval resulting from this two‐stage procedure and the confidence interval that is always centered on the feasible generalized least squares estimator, as follows. First, we compare the coverage probability functions of these confidence intervals. Second, we compute the scaled expected length of the confidence interval resulting from the two‐stage procedure, where the scaling is with respect to the expected length of the confidence interval centered on the feasible generalized least squares estimator, with the same minimum coverage probability. These comparisons are used to choose the better confidence interval, prior to any examination of the observed response vector.     

An Empirical Analysis of Analysts' Capital Expenditure Forecasts: Evidence from Corporate Investment Efficiency*

We examine whether the information conveyed in a relatively new analyst research output—capital expenditure (capex) forecasts—affects corporate investment efficiency. We find that firms with analyst capex forecasts exhibit higher investment efficiency. This effect is stronger when the forecasts are issued by analysts with higher ability or greater industry knowledge. Moreover, the effect of capex forecasts on investment efficiency varies with the signals they convey about future growth opportunities—positive-growth signals are more effective in reducing underinvestment, while negative-growth signals are more effective in reducing overinvestment. Cross-sectional tests suggest that these effects operate at least in part through both a financing channel and a monitoring channel. Taken together, our results suggest that analysts' capex forecasts convey useful information about firms' growth opportunities to managers and investors, which can facilitate efficient investment.     

基于同轴电缆的移动信号室内深度覆盖系统设计与实现

针对移动信号室内深度覆盖需求和现有覆盖方案存在的问题，提出了一种以有线电视同轴电缆为入户通道的射频系统。分析了系统原理和几个关键问题，计算了系统各项设计参数，阐述了合路器、跨路器和智能终端三个主要部分的结构及阻抗匹配滤波、同步、放大等关键模块的实现方法。实地测试结果表明，系统各项指标符合设计和应用要求，实现了160 m2高层住宅的信号覆盖，提高了小区测量报告（MR）覆盖率，同时对移动室分系统性能也无影响。所提方案与现有方案相比具有低成本、施工快速、协调简单等优势，是一种新颖实用的室内深度覆盖实现方式。     

Towards a Routine External Evaluation Protocol for Small Area Estimation

Statistical criteria are needed by which to evaluate the potential success or failure of applications of small area estimation. A necessary step to achieve this is a protocol—a series of steps—by which to assess whether an instance of small area estimation has given satisfactory results or not. Most customary attempts at evaluation of small area techniques have deficiencies. Often, evaluation is not attempted. Every small area study requires an external evaluation. With proper planning, this can be routinely achieved, although at some cost, amounting to some sacrifice of efficiency of global estimates. We propose a Routine External Evaluation Protocol to allow us to judge whether, in a given survey, small area estimation has led to accurate results and sound inference.     

董事高管责任保险与企业财务困境风险——基于A股上市公司的经验证据

以2006-2015年A股上市公司为样本,检验董事高管责任保险对企业财务困境风险的影响及其作用机制。研究发现：购买董事高管责任保险有助于降低企业的财务困境风险,保险公司的监督作用是企业财务困境风险降低的主要原因;高质量的内部控制或较多的分析师跟踪能减弱董事高管责任保险对企业财务困境风险的治理效用;产权性质则未产生显著的影响。     

The determinants of analyst-firm pairings

This paper explores the determinants of observed analyst-firm pairings. We adopt an analyst/brokerage house perspective that allows us to examine not only firm-level characteristics as in prior research, but also attributes of the analyst and the analyst’s brokerage house that may drive these pairings. Our empirical analyses provide two primary insights. First, analyst characteristics such as industry expertise and relative experience, and brokerage house characteristics such as continuity of coverage, are associated with the decision to follow a firm. Second, there is substantial variation in the association between firm, analyst, and brokerage house characteristics and the decision to follow a firm; this occurs across individual analysts as well as across different types of brokerage houses. Overall, our results provide further insights into the factors leading to observed analyst-firm pairings, and indicate that these factors vary across analysts and their brokerage houses – suggesting richer associations than the average firm-level relationships documented by prior research.     

Statistically based quarterly earnings expectation models for nonseasonal firms

We present empirical evidence on the relative predictive power of statistically based quarterly earnings expectation models for firms that are characterized as nonseasonal in nature. We are particularly interested in nonseasonal firms for two reasons. First, it appears that a sizable and growing percentage of firms exhibit quarterly earnings patterns that are clearly nonseasonal in nature. We present new evidence that is consistent with this trend. Specifically, 36% of our sample firms (n = 296) are nonseasonal compared to 12% reported in Lorek and Bathke (J Acc Res 22:369–379, 1984) (n = 29); 17% in Brown and Han (J Acc Res 38:149–164, 2000) (n = 155); and 28.2% in Bathke et al. (J Business Inquiry 5:39–49, 2006) (n = 167). Second, we also find that 43.6% of the nonseasonal firms in our sample have no analyst coverage. Therefore, interest in the predictive ability of statistically based models for such firms is greatly enhanced. Our predictive findings indicate that the random walk model provides significantly more accurate pooled, one-step ahead quarterly earnings predictions across 40 quarters in the 1994–2003 holdout period than the first-order autoregressive model popularized in the literature. We attribute the superior performance of the random walk model to at least three contributing factors: (1) its parsimonious nature; (2) the reduced levels of autocorrelation observed in our quarterly earnings data relative to previous work; and (3) a significantly greater frequency of loss quarters evidenced by nonseasonal versus seasonal firms.

新型农村养老保险制度的财政负担测算——兼论“十二五”期间实现全覆盖的可行性

本研究对新型农村养老保险制度的财政负担进行了测算,研究表明：在低水平、全覆盖目标下,到2020年各级财政累计总投入可以控制在9000亿元左右,中央财政投入占到70%以上;若＂十二五＂期间提前实现全覆盖,到2015年中央财政累计投入将不超过3000亿元,地方财政累计投入将不超过1200亿元;全覆盖实现后中央财政每年投入约700亿元可以保障新农保制度运行;提前实现全覆盖不会大幅度增加未来10年财政总投入,而主要对今后几年的财政投入提出相对更高要求。＂十二五＂期间实现全覆盖总体上不会对中央和地方财政造成太大负担,但是,经济欠发达地区地方财政（尤其县级财政）分担压力不容忽视。全覆盖目标的提前实现要求＂十二五＂期间加大中央财政投入,以递增的速度提高新农保覆盖率,加大对中西部地区政策倾斜力度,引导地方政府积极配合。     

城市化视角下高密度建设区域通风潜力分析——以上海市中心城区为例

随着城市化的推进,城市的下垫面情况发生了巨大的改变,从过往的农田、水系、绿地变为建筑、道路等人工环境。城市下垫面的改变,将对城市的通风潜力造成较大影响,进而影响到城市热岛、大气污染、室外舒适度等问题。传统城市规划中,主要着眼于土地的空间利用,而较少考虑城市通风潜力问题。在全球气候变化影响下,上海作为高密度发展的代表性城市,未来将面临较大的气候风险,在此背景下,本文通过建筑密度、建筑高度、水系覆盖率、绿地覆盖率四个指标及其综合影响对上海展开城市通风潜力研究,并结合未来的规划发展提出建议,具有重要的现实与指导意义。