ESTIMATION OF VALUE AT RISK AND RUIN PROBABILITY FOR DIFFUSION PROCESSES WITH JUMPS

In this paper we give upper bounds for both the Value at Risk   VaR _α,  0 < α < 1  , and for ruin probabilities associated with the supremum of a process driven by a Brownian motion and a compound Poisson process. We obtain lower bounds for the same Value at Risk, and for different cases we discuss the behavior of the bounds for small α. We prove our bounds are "asymptotically" optimal, as α tends to zero. The ruin probabilities obtained are related to other bounds found in recent literature.     

Efficient local IV estimation of an empirical auction model

In this paper we examine semiparametric efficiency bounds and efficient estimators for the case of a linear local instrument variable (LIV) model under the assumptions studied in Abadie et al. (2002). We apply the semiparametrically efficient estimation method to analyze the relation between bid dispersion and early bidding in an online auction dataset, which is collected from a natural experiment conducted in Nekipelov (2007). The results confirm the theoretical findings developed in Nekipelov (2007). The semiparametric efficient estimation procedure substantially improves the statistical significance of the effect of jump bidding on bid dispersion.     

Flexible Estimation of Copulas: An Application to the US Housing Crisis

Zimmer (‘The role of copulas in the housing crisis’, Review of Economics and Statistics 2012; 94 : 607–620) provides an interesting case study of the pitfalls of using parametric copulas to understand the US housing crisis in the latter part of 2000s. The original study by Zimmer (2012) employs a finite‐mixture copula to illustrate that the symmetry of the Gaussian copula may not be tenable, especially for US housing price data during the time period from 1975:Q2 to 2009:Q1. We undertake a replication of his study in a wide sense. First, we replicate the study by incorporating revised data and then extending the dataset to include the most recent data. Second, we implement a nonparametric copula estimator recently proposed by Racine (‘Mixed data kernel copulas’, Empirical Economics forthcoming) to the parametrically filtered data used in Zimmer (2012). Our replication finds that the application of the nonparametric copula to the same and extended filtered data provides an alternative flexible specification for copulas. However, the overall cautionary message of the flexible‐form copula espoused in Zimmer (2012) remains. Copyright © 2015 John Wiley & Sons, Ltd.     

Analysis and design of focused demand chains

The paper describes the evolution of focused demand chains over an extended period of time as a major UK lighting manufacturer has sought to remain an international player in a fast changing business environment. Analysis and design procedures make use of the concepts of Wickham Skinner and Marshall Fisher to answer the strategic questions “what facilities are required and how should they be laid out to enable the necessary focused demand chains?” and to answer the tactical question “which focused demand chain is appropriate for this product?” The case study then details how the company has been transformed from operating within a traditional supply chain to driving change via the engineering of four focused demand chains. The paper concludes with a comparison of operations enablers, customer choice, and business performance metrics covering the transition period culminating in the current focused demand chain scenario. By matching products to the appropriate value stream there is a consequential reduction in product development time of 75%; manufacturing costs reduction of up to 27%; and up to 95% reduction in delivery lead times.     

Index

Other Index

Index     

Becoming A Leader In A Complex Organization

For a new leader, the process of entering and establishing a position of leadership in a complex organization presents a major challenge. This challenge seems particularly acute when authority, goals and technology are ambiguous, as in many professional service organizations. In this paper, we integrate ideas from the literature on socialization and role theory as well as that on executive succession processes to view new leader integration as a mutual adjustment process between two trajectories – that of the organization and that of the new leader. It is argued that this may lead to four possible types of integration outcomes: assimilation, transformation, accommodation and parallelism. Drawing on a case study of a large hospital, the paper identifies several mechanisms that can be mobilized by the new leader to enhance his or her room for manœuvre as the integration process evolves. The mechanisms can be classified as collaborative or affirmative, with each type having different risks and advantages. The case analysis further reveals that leader integration processes may be differentiated between different activity domains, dynamic over time (as the use of one type of integration approach alters the potential for another later), and interactive across different activity domains (as events in one part of the organization have consequences for those occurring in another).     

On the convergence of the critical values of uniformly most powerful unbiased tests for two-sided hypotheses

Summary The behavior of the critical values of two-sided uniformly most powerful unbiased tests is studied under the condition of weak convergence of the distribution of the test statistic.     

Gender and ethnic differences in factors that influence food intake

Abstract The objective of this research was to ascertain the gender-and ethnic-related factors that influence what one eats. This survey was conducted using a validated, pilot-tested questionnaire in 11 states and the District of Columbia, which were participating in the W-182 Western Regional Research project. The results indicated that the factors that influence what one eats differ by gender and ethnicity. Men were very much influenced by likes and dislikes, and by their spouse or significant other. Women were influenced by likes and dislikes, and health. Food likes/dislikes and concerns about health and weight were among the leading four factors for all ethnic groups. Food likes/dislikes were the top factor influencing what is eaten by 51% or more of Asians, Pacific Islanders, Caucasians and Hispanics. Concern about health was the top factor for 62% and 58%, respectively, of African Americans and Native Americans.