Bootstrapping I(1) data

A functional law is given for an I(1) sample data version of the continuous-path block bootstrap of Paparoditis and Politis (2001a). The results provide an alternative demonstration that continuous-path block bootstrap unit root tests are consistent under the null.     

A systematic review of cost-effectiveness modeling of pharmaceutical therapies in neuropathic pain: variation in practice,key challenges,and recommendations for the future

Objectives: Complexities in the neuropathic-pain care pathway make the condition difficult to manage and difficult to capture in cost-effectiveness models. The aim of this study is to understand, through a systematic review of previous cost-effectiveness studies, some of the key strengths and limitations in data and modeling practices in neuropathic pain. Thus, the aim is to guide future research and practice to improve resource allocation decisions and encourage continued investment to find novel and effective treatments for patients with neuropathic pain.

Methods: The search strategy was designed to identify peer-reviewed cost-effectiveness evaluations of non-surgical, pharmaceutical therapies for neuropathic pain published since January 2000, accessing five key databases. All identified publications were reviewed and screened according to pre-defined eligibility criteria. Data extraction was designed to reflect key data challenges and approaches to modeling in neuropathic pain and based on published guidelines.

Results: The search strategy identified 20 cost-effectiveness analyses meeting the inclusion criteria, of which 14 had original model structures. Cost-effectiveness modeling in neuropathic pain is established and increasing across multiple jurisdictions; however, amongst these studies, there is substantial variation in modeling approach, and there are common limitations. Capturing the effect of treatments upon health outcomes, particularly health-related quality-of-life, is challenging, and the health effects of multiple lines of ineffective treatment, common for patients with neuropathic pain, have not been consistently or robustly modeled.

Conclusions: To improve future economic modeling in neuropathic pain, further research is suggested into the effect of multiple lines of treatment and treatment failure upon patient outcomes and subsequent treatment effectiveness; the impact of treatment-emergent adverse events upon patient outcomes; and consistent and appropriate pain measures to inform models. The authors further encourage transparent reporting of inputs used to inform cost-effectiveness models, with robust, comprehensive and clear uncertainty analysis and, where feasible, open-source modeling is encouraged.     

The effects of supplier capabilities on industrial customers’ loyalty: the role of dependence

This research examines whether suppliers’ capabilities impact OEM customers’ dependence on the supplier and thereby generate customer loyalty. Using a sample of purchasing managers focusing on a single key component supplier, we examine three supplier capabilities, two dependence dimensions, and three aspects of customer loyalty. Core offering capability increases the customer firm’s benefit-based dependence. Operations capability has a more comprehensive effect, enhancing both benefit-based and cost-based dependence. Benefit-based dependence leads to relational loyalty and, through its effect on relational loyalty, to insensitivity to competitive offerings and future purchase expansion. Cost-based dependence motivates insensitivity to competitive offerings, but does not affect relational loyalty or purchase expansion. The supplier’s communication capability is associated with relational loyalty, but this effect does not flow through the customer firm’s dependence. The divergent pattern of antecedents and effects of benefit-based dependence and cost-based dependence may explain the inconsistent and insignificant research findings in previous research on dependence. Our results suggest that adopting a bi-dimensional model of dependence more fully captures the theoretical domain of dependence, thereby permitting researchers to better examine its role in supply chain, channel, and marketing relationships.     

A two-stage realized volatility approach to estimation of diffusion processes with discrete data

This paper motivates and introduces a two-stage method of estimating diffusion processes based on discretely sampled observations. In the first stage we make use of the feasible central limit theory for realized volatility, as developed in [Jacod, J., 1994. Limit of random measures associated with the increments of a Brownian semiartingal. Working paper, Laboratoire de Probabilities, Universite Pierre et Marie Curie, Paris] and [Barndorff-Nielsen, O., Shephard, N., 2002. Econometric analysis of realized volatility and its use in estimating stochastic volatility models. Journal of the Royal Statistical Society. Series B, 64, 253–280], to provide a regression model for estimating the parameters in the diffusion function. In the second stage, the in-fill likelihood function is derived by means of the Girsanov theorem and then used to estimate the parameters in the drift function. Consistency and asymptotic distribution theory for these estimates are established in various contexts. The finite sample performance of the proposed method is compared with that of the approximate maximum likelihood method of [Aït-Sahalia, Y., 2002. Maximum likelihood estimation of discretely sampled diffusion: A closed-form approximation approach. Econometrica. 70, 223–262].     

Economic transition and growth

Some extensions of neoclassical growth models are discussed that allow for cross‐section heterogeneity among economies and evolution in rates of technological progress over time. The models offer a spectrum of transitional behavior among economies that includes convergence to a common steady‐state path as well as various forms of transitional divergence and convergence. Mechanisms for modeling such transitions, measuring them econometrically, assessing group behavior and selecting subgroups are developed in the paper. Some econometric issues with the commonly used augmented Solow regressions are pointed out, including problems of endogeneity and omitted variable bias which arise under conditions of transitional heterogeneity. Alternative regression methods for analyzing economic transition are given which lead to a new test of the convergence hypothesis and a new procedure for detecting club convergence clusters. Transition curves for individual economies and subgroups of economies are estimated in a series of empirical applications of the methods to regional US data, OECD data and Penn World Table data. Copyright © 2009 John Wiley & Sons, Ltd.     

Utilizing a Value of Information Framework to Improve Ore Collection and Classification Procedures

This case study utilizes a value of information decision framework to provide mine managers guidance regarding the purchase of ore grade scanners. LKAB's Kiruna mine produces three types of iron ore to meet long-term contractual agreements on a monthly basis. There is a priori uncertainty regarding the ore type in any given mineable section of the orebody. In addition, there is extracted ore type uncertainty that is introduced by the mining process. These uncertainties are better understood by obtaining more precise (real-time) information. In addition, a better understanding of the uncertainties can improve the quality of operational decisions and increase the overall profitability of the mine. This case study provides a framework for measuring the economic impact of information purchases in a mining context and discusses the implications of those findings.     

Marketing’s roles in innovation in business-to-business firms: Status, issues, and research agenda

A project funded by the Institute for the Study of Business Markets to develop an understanding of the current state of business-to-business marketing and a research agenda for the field identified a lack of understanding of how the marketing function can or should best contribute to firms’ innovation efforts as the top priority. A workshop of senior academics and research-oriented practitioners explored this topic further, identifying four specific themes: (1) improving customer needs understanding and customer involvement in developing new products, (2) innovating beyond the lab, (3) disseminating and implementing research findings in firms, and (4) marketing’s overall role in innovation. This article defines these themes, sketches the current status of knowledge about each theme, frames practitioners’ issues with them, and proposes research agendas for each theme to move the field forward. The goal is to encourage rigorously executed academic research that can also help firms innovate more successfully.     

Building entrepreneurial tie portfolios through strategic homophily: The role of narrative identity work in venture creation and early growth

In this article, we present the results of a case study of an entrepreneur who successfully founded and grew a venture underpinned by a portfolio of strongly homophilous, dyadic ties. Building on our case, we discuss how the entrepreneur strategically constructed these ties through a form of narrative identity work, explore the shared identity narratives that he used to do so, and highlight the heterogeneous nature of the resulting tie portfolio. We go on to explore the factors that motivated the entrepreneur to purposefully construct an entrepreneurial tie portfolio in this way. Building on our findings, we discuss the nature of narrative identity work and its role in creating homophilous ties, explore the connection between the resulting shared identity narratives and trust, and discuss the central role of values in strategic homophily.