Concentration behavior of the penalized least squares estimator

Consider the standard nonparametric regression model and take as estimator the penalized least squares function. In this article, we study the trade‐off between closeness to the true function and complexity penalization of the estimator, where complexity is described by a seminorm on a class of functions. First, we present an exponential concentration inequality revealing the concentration behavior of the trade‐off of the penalized least squares estimator around a nonrandom quantity, where such quantity depends on the problem under consideration. Then, under some conditions and for the proper choice of the tuning parameter, we obtain bounds for this nonrandom quantity. We illustrate our results with some examples that include the smoothing splines estimator.     

The long overhang of bad decisions in agro-industrial development: Sugar and tomato paste in Ghana

In theory, learning from past mistakes should result in adapted and improved development policy. However policy learning can be difficult to achieve, and the link between learning and policy change is neither direct nor immediate. In this study we look at learning in agro-industrial policy in Ghana, by tracing the interest in sugar production and tomato processing over six decades. Specifically we ask why four failed factories established in the early 1960s have continued to play central roles in both policy and public discourse. Using policy documents, academic material, and the popular press, we show that Ghana’s policy focus on sugar production and tomato processing has endured, despite the fact that the factories were misconceived, poorly sited, ill-equipped and poorly managed. Indeed, the political ideas that underpinned the establishment of these factories in the early days of independence can be seen in the current One District, One Factory policy. We suggest that it is their symbolic and political value, not their economic value, which keeps the discussion around these factories alive. Even when shut down, they are a physical manifestation of historic commitments by the state, and as such they guarantee the attention of politicians, and hold out hope of a next re-launch. Unfortunately as long as the factories continue to be incorporated into each new generation of agro-industrial policy, it is difficult for any alternatives to gain traction. This analysis highlights the very long overhang of bad decisions, particularly when they are associated with physical infrastructure. Learning from past mistakes will only happen if the short-term political cost of turning policy learning into policy action can be overcome.     

The role of the entrepreneurial encounter in the emergence of opportunities: Vallée’s Dallas Buyers Club

ABSTRACT

This paper aims to explore the conceptual potential of the Deleuzian notion of the encounter in order to better understand the genealogy of opportunities. We adopt a processual perspective of opportunities. In order to translate this notion to the domain of entrepreneurship, we analysed and interpreted Jean-Marc Vallée’s Dallas Buyers Club. This film follows the creation of the first club in the United States that illegally allowed HIV-positive people to supply themselves with foreign antiretroviral drugs from Mexico or Japan. The article highlights encounters in this process that disturb the entrepreneur’s belief systems and allow him or her to be open to potential opportunity. It finally explores how the encounter may improve our understanding of the political becoming of opportunities within the entrepreneurial process.     

Board directors with foreign experience and stock price crash risk: Evidence from China

This study examines the impact of board directors with foreign experience (BDFEs) on stock price crash risk. We find that BDFEs help reduce crash risk. This association is robust to a series of robustness checks, including a firm fixed effects model, controlling for possibly omitted variables, and instrumental variable estimations. Moreover, we find that the negative association between BDFEs and crash risk is more pronounced for firms with more agency problems, weaker corporate governance, and less overall transparency. Our findings suggest that the characteristics of board directors matter in determining stock price crash risk.     

A play-the-winner-type urn design with reduced variability

We propose a new adaptive allocation rule, the drop-the-loser, that randomizes subjects in the course of a trial comparing treatments with dichotomous outcomes. The rule tends to assign more patients to better treatments with the same limiting proportion as the randomized play-the-winner rule. The new design has significantly less variable allocation proportion than the randomized play-the-winner rule. Decrease in variability translates into a gain in statistical power. For some values of success probabilities the drop-the-loser rule has a double advantage over conventional equal allocation in that it has better power and assigns more subjects to the better treatment. Acknowledgments. I thank Stephen Durham, the associate editor, and the referees for their helpful suggestions.     

Determination of Discrete Spectrum in a Random Field

We consider a two dimensional frequency model in a random field, which can be used to model textures and also has wide applications in Statistical Signal Processing. First we consider the usual least squares estimators and obtain the consistency and the asymptotic distribution of the least squares estimators. Next we consider an estimator, which can be obtained by maximizing the periodogram function. It is observed that the least squares estimators and the estimators obtained by maximizing the periodogram function are asymptotically equivalent. Some numerical experiments are performed to see how the results work for finite samples. We apply our results on simulated textures to observe how the different estimators perform in estimating the true textures from a noisy data.     

Sources, uses, and forms of data in the new product development process

This paper presents qualitative and exploratory research investigating the role that managing knowledge and information plays in new product development (NPD). A set of 20 in-depth interviews uncovered eight basic types of information used throughout the NPD process and three general approaches to managing information needed in the NPD process. Although some exemplary companies seem to do an outstanding job of collecting and disseminating information, the majority of firms struggle. NPD process automation solutions tackle part of the problem, ignoring nonquantitative data forms and the full picture of information use throughout the entire development process.     

以创新创业基地建设促进物流实验室发展

该文主要阐述了怎样通过建设一个创新创业基地的架构,即管理思路、组织原则、创新流程等一系列实验室管理模式,来提供给管理类大学生一个得到实践锻炼的良好平台,同时也促进管理类专业实验室合理有效的管理。     

如何抓住国企改制的关键——一个国企改制失败引发的思考

动态联盟 (VirtualEnterpriseAlliance,VEA是 2 1世纪信息社会生产的主流组织形式 ,选择和确定联盟伙伴是建立动态联盟的关键环节之一。盟员的正确选择对提高联盟企业的总体竞争力有着极其重要的作用。本文在构建动态联盟盟员的实施评价体系基础上 ,提出一个修正的AHP算法 ,     

中国工业化进程与劳动力就业关系研究综述

工业化进程的加速推进与劳动力就业在一定程度上是存在矛盾的,国内外众多专家学者对这一问题也做了相应研究。文章分别从加速工业化进程对劳动力就业的抑制、促进和新型工业化与劳动力就业三方面对现有文献进行了梳理,并进行了评述,为进一步研究提供了理论基础和研究空间。今后进一步研究的方向主要是工业化进程与劳动力就业相互影响的内部机理,以为合理工业化路径选择和有效的劳动力就业模式提供理论支持。