Left truncated right censored (LTRC) data arise quite commonly from survival studies. In this article, a model based on piecewise linear approximation is proposed for the analysis of LTRC data with covariates. Specifically, the model involves a piecewise linear approximation for the cumulative baseline hazard function of the proportional hazards model. The principal advantage of the proposed model is that it does not depend on restrictive parametric assumptions while being flexible and data-driven. Likelihood inference for the model is developed. Through detailed simulation studies, the robustness property of the model is studied by fitting it to LTRC data generated from different processes covering a wide range of lifetime distributions. A sensitivity analysis is also carried out by fitting the model to LTRC data generated from a process with a piecewise constant baseline hazard. It is observed that the performance of the model is quite satisfactory in all those cases. Analyses of two real LTRC datasets by using the model are provided as illustrative examples. Applications of the model in some practical prediction issues are discussed. In summary, the proposed model provides a comprehensive and flexible approach to model a general structure for LTRC lifetime data.

Often in reliability studies we observe failure-time data with two dependent failure modes. In this article, by using a bivariate Weibull model with distinct shape parameters, we present a model for reliability data with two dependent failure modes. Inferential methods for the proposed model are discussed. The efficacy of the methods of inference is assessed through a Monte Carlo simulation study, and it is observed that the model and methods perform satisfactorily. An issue of practical interest for reliability engineers is to predict field failures at a future time. Prediction methods are developed in this setting. For illustrative purposes, analysis of a real dataset on failure of a device is presented. In summary, the model and methods presented in this article provide a comprehensive treatment for analyzing reliability data with two dependent failure modes.

The two-dimensional estimation problem of the arbitrage-free option price surface from available best bid-ask quotes is difficult to solve due to insufficient as well as skewed quotes for various strikes and maturities besides the prevalence of arbitrage opportunities in the observed quotes. This article presents a semi-closed form approximation for constructing an arbitrage-free European call option price surface from the observed quotes. The estimated option pricing surface is represented as an interpolation-based convex combination of shape-restricted Bernstein polynomials. A fast and straightforward surface-fitting algorithm is presented based on the quadratic programming method. This research also includes a simulation utilizing the Heston stochastic volatility model to evaluate the proposed method. The empirical applicability of the proposed method is demonstrated using S&P 500 call option price data.

We compare equal treatment and affirmative action policies in Tullock contests. Equal treatment means that agents who exert equal effort have an equal probability of success. In affirmative action, agents who incur an equal cost of effort have an equal probability of success. Finite player contests with non-linearities in impact and cost functions cannot be solved in closed form. Instead, we approximate them with large population contests with measure zero agents. Affirmative action reduces aggregate effort in such contests, which can be solved. However, it ensures equality without any significant loss of aggregate welfare. We verify these findings for finite player contests through numerical simulations. For a sufficiently large number of players, the numerical simulations support the results of the large population analysis.

Dalits are a historically marginalized caste group in India. In this study, we examine the impact that the institution of caste has on career change. Focusing on the shift from science, technology, engineering, and mathematics (STEM) to non-STEM careers, we ask why members of the Dalit communities in India leave their STEM careers. To present a comprehensive understanding of this career change, we also examine the factors that facilitate their retention in STEM careers. Deriving data from in-depth interviews with 42 STEM scholars from the Dalit communities in India, we illustrate their organizational experiences that are based on casteism. Qualitative data analyses were done using the grounded theory method. Results suggest that while caste operates in a unique way to drive away Dalit scholars from their STEM careers, doing gender plays an important role in their retention within the same careers.

This paper presents an extension of maxmed mechanisms introduced by Sprumont (J Econ Theory 148:1102-1121, 2013) to the multiple homogeneous object setting. To address the complexities of the multiple objects setting, we consider special families of mechanisms, which contain a mechanism for each possible number of available objects. We interpret these families as ex-ante sale procedures, which specify different mechanisms to allocate different quantities of objects. We identify and completely characterize the maxmed families, which use the (extended) maxmed mechanisms to allocate any number of available objects while using the same non-negative reserve price. The maxmed families turn out to be the only families that are Pareto optimal among well-behaved families comprising mechanisms that satisfy a set of desirable axioms including the ones used by Sprumont (J Econ Theory 148:1102-1121, 2013) : anonymity, strategyproofness, no-envy, feasibility and individual rationality.

Although health information systems (HIS) play an important role in elevating health standards, a comprehensive understanding of how to effectively implement HIS in rural areas is lacking. This issue becomes more significant when considering that globally a majority of the approximately 1.5 million deaths of children under the age of five in 2019 that were attributable to vaccine-preventable diseases occurred in rural areas. Accordingly, we ask two questions. How does rurality influence the implementation of information and communication technology for development (ICT4D) projects? How do organisations navigate challenges associated with rurality during the implementation of these projects? Our findings, derived from an in-depth case study of a social enterprise in rural India, reveal two paradoxes that pose challenges to the effective implementation of HIS in rural settings: the localisation paradox and the cultural embedding paradox. We found that contextually balanced engagement was comprised of four organisational responses-prioritising; localising; cultural adjustment; and engaging stakeholders-that help navigate the challenges posed by the localisation and cultural embedding paradoxes. Synthesising these findings, we develop a process model that shows how the implementation of HIS in rural areas is shaped by the descriptive and sociocultural characteristics of rurality. Further, organisations require a dynamic approach, engaging in multiple responses over time to navigate the paradoxes inherent in HIS implementation. We suggest that organisational responses to paradoxical tensions stemming from the descriptive and sociocultural characteristics of rurality lead to the development of HIS enabled for rurality. Our findings contribute the understanding of ICT4D projects implementation.

Drawing from Conservation of Resources theory, the present study examines a serial mediation model in which competitive climate predicts work-to-family conflict via two mediators - first, excessive and compulsive workaholism, and then emotional exhaustion. As organizations may differ in terms of their competitive climate, we test our model based on data collected from public (Study 1) and private (Study 2) sector organizations. In study 1 (n = 282), two waves of data with a 2-week interval were obtained from full-time Indian managerial employees working in the public sector organizations. Results supported our hypothesized mediation model. In Study 2 (n = 250), we replicated the finding of Study 1 with private sector-based organizations. Across two field studies, we found general support for our hypotheses. The present study contributes to understanding of the underlying mechanisms explaining the negative spillover effect of competitive climate on work-to-family interface.

Envy fuels luxury consumption-both real and fake. Through three studies, we show that benign envy motivates online shoppers to purchase authentic luxury products, whereas malicious envy encourages counterfeiting. By triggering envy through its antecedents of deservingness and pride, we show that benign (malicious) envy motivates a general tendency towards moral (immoral) behavior, which has distinct downstream effects on consumer attitude towards luxury. Benign envy increases belief in the moral virtue of hard work, thereby inspiring consumers to aspire and strive for original luxury products. Whereas malicious envy triggers moral disengagement-dissolving the moral dilemma associated with counterfeiting. Malicious envy also makes consumers appraise luxury corporations as immoral-fueling the desire to punish the brand through counterfeiting. The effects hold for both brand-generated envy and incidental envy. The findings have important implications for luxury branding to help control consumer demand for counterfeits.

While firms engage stakeholders in their sustainability practices to contribute to a better world resiliently and responsibly, little is known about what drives their ability to generate customer engagement (CE) and supplier engagement (SE) for sustainability purposes. This paper identifies, theorizes, and empirically validates the differential roles of board oversight and incentivization, along with contingencies (a chief marketing officer's (CMO) presence and governance disclosure), in driving CE and SE. Using data from 308 firms, the paper finds that while board oversight and incentivization positively affect CE, only incentivization positively affects SE. The paper also finds significant moderation effects of CMO presence and governance disclosure. Through multiple post hoc analyses, the paper explores how CE and SE influence firm performance. The paper provides a nuanced understanding of incentive types' effects and contributes to the literature on grand challenges connecting firms' strategies and sustainability objectives to customer and supplier engagement.

PurposeThe objective of our study is to understand the factors associated with non-adherence to the physician's follow-up advice by persons with glaucoma.MethodsWe use a four-year panel dataset containing demographic, clinical, and intervention details and doctor's advised follow-up date for a random sample of 2,622 glaucoma patients from an Indian tertiary eye care hospital. We model this unique advised follow-up date in multivariate logistic regressions to identify factors associated with patients' coming early or late as against on-time. An OLS regression also examines an association between delayed follow-up and declining visual acuity.ResultsDemographic variables such as age, gender, distance to hospital, IOP, and visual acuity were not associated with delayed adherence to follow-up. Patients advised to review within 2 months (p < .001), paying patients (p < .001), and those habituated to routine follow-up (diabetes patients) (p < .01) are less likely to delay care-seeking. Patients are more likely to come on-time in visits immediately after clinical interventions relative to later ones (p < .001). Our second analysis reveals the presence of cataract and the very first post-surgery visit as factors influencing patients to come early. Our third analysis reveals that a higher proportion of delayed visits had resulted in worsening of vision in the glaucoma-affected eye.ConclusionOur results suggest that active counselling by doctors, especially for routine follow-up visits, can help in better follow-up adherence and prevention of glaucoma-related visual impairment.

Examples of units with two performance characteristics that degrade over time are ubiquitous in reliability engineering. In this article, we develop a flexible model for bivariate degradation data pertaining to units in which the degradation processes corresponding to the performance characteristics are likely dependent on each other. The proposed model has two features: the degradation processes are marginally modelled by gamma processes, and the dependence between them is modelled by a shared frailty term that is assumed to follow the generalized gamma distribution. We show that this model is far more flexible and efficient than many of the commonly used models for capturing dependence between the performance characteristics. A computational technique for the maximum likelihood estimation, based on Monte Carlo simulation, is developed for the proposed model. Then, the method of estimation is evaluated through an elaborate Monte Carlo simulation study. The joint reliability function of the unit with two performance characteristics and its estimation are also discussed in this general setting. The proposed model is extended to the case of multiple performance characteristics. Finally, a case study is presented in which a real degradation data pertaining to fatigue cracks is analysed through the proposed model to demonstrate its usefulness.

The growing need for academic impact requires researchers to develop and address important ideas. In this paper, we analyze how theory has been framed and operationalized within international business scholarship, which has a long tradition of producing research that accounts jointly for multiple research contexts and levels of analysis. We focus on two key aspects of published articles: the complexity of their research questions and how the research questions are translated into testable hypotheses. We further assess how the complexity and operationalization of research questions have been received by business/management, interdisciplinary, and practice-oriented research audiences. To achieve this, we examine a sample of 423 quantitative articles published in the Journal of International Business Studies between 2005 and 2015, and consider the articles' citations during 2010-2020. Our paper provides suggestions about how authors might better frame research questions that are both important and impactful.

This article aims to explain the heterogeneity in individual purchasing decisions toward electric vehicles (EVs). To achieve this, we conducted a stated preference experiment among Indian consumers regarding EV adoption, using a two-stage integrated choice and latent variable model. Neoclassical and lifestyle theory is employed to examine consumers' purchasing decisions. Our findings indicate that consumers place more emphasis on the purchase price of EVs rather than the annual savings accrued from EV usage. Additionally, we observe that risk-averse behavior is negatively, while social influence is positively associated with the consumer's likelihood toward EVs. We categorize consumers into three segments: conservative, indifferent, and enthusiast, to explain the heterogeneity in their preferences based on the charging station availability, annual usage, and household income. The article reveals that consumers in regions with fewer charging stations or those with low vehicle usage are more risk-averse compared to those in regions with a higher density of charging stations or higher vehicle usage. Regarding demographics, younger consumers and those with prior car experience are more inclined to adopt EVs. This article provides valuable insights that could assist governments and policymakers in formulating strategies to facilitate the adoption of EVs.

Biodiversity of large wild mammals is declining at alarming rates worldwide. It is therefore imperative to develop effective population conservation and recovery strategies. Population dynamics models can provide insights into processes driving declines of particular populations of a species and their relative importance. But there are insufficient tools, namely population dynamics models for wild herbivores, for characterizing their decline and for guiding conservation and management actions. Therefore, we have developed a model which can serve as a tool to fill that void. Specifically, we develop an integrated Bayesian state-space population dynamics model for wildlife populations and illustrate it using a topi population inhabiting the Greater Mara-Serengeti Ecosystem in Kenya and Tanzania. The model integrates ground demographic survey with aerial survey monitoring data. It incorporates population age and sex structure and life history traits and strategies and relates birth rates, age-specific survival rates and sex ratios with meteorological covariates, prior population density, environmental seasonality and predation risk. It runs on a monthly time step, enabling accurate characterization of reproductive seasonality, phenology, synchrony and prolificacy of births, juvenile and adult recruitments. Model performance is evaluated using balanced bootstrap sampling and by comparing model predictions with empirical aerial population size estimates. The hierarchical Bayesian model is implemented using MCMC methods for parameter estimation, prediction and inference and reproduces several well-known features of the Mara topi population, including striking and persistent population decline, seasonality of births, juvenile and adult recruitments. It is general and can be readily adapted for other wildlife species and extended to incorporate several additional useful features. Supplementary materials accompanying this paper appear on-line.

Based on conservation of resources theory, the present study examines a serial mediation model in which empowering leadership predicts the nature of work-home interfaces via cognitive states and processes (interactional justice and work rumination). Two waves of data with a one-month interval were obtained from 195 full-time Korean employees. Structural equation modeling assessed mediation, first by two forms of interactional justice (interpersonal and informational) and then by two forms of work rumination (positive and negative). The results generally supported the mediation model showing that empowering leaders helped subordinates' work-home enrichment, because they enhanced both interpersonal and informational justice, resulting in positive rumination about their work experiences. Empowering leaders also helped reduce subordinates' work-home conflict through enhancing informational justice, which made employees ruminate less about negative aspects of work during off-job time. Testing alternative models that added more direct paths did not improve model fit. Overall, the study contributed to understanding the underlying cognitive mechanisms explaining the effect of empowering leadership on work-home spillover.

We posit that high search intensity on a firm's SEC filings creates capital market pressure on managers to withhold bad news. Using the count of non-robot EDGAR downloads of SEC filings as a proxy for search intensity, we find that high search intensity is related to higher future crash risk. The result is cross-sectionally stronger for firms with higher transient institutional holdings, overconfident CEOs, and more intangibles. Our findings are robust to different measures of crash risk and bad news hoarding. Overall, we highlight one unintended capital market consequence associated with the high intensity of information acquisition.

Our research addresses how organizations manage a shift from a single to a hybrid identity, a question that the identity literature still is grappling with. We address this question by reflecting on how organizations develop hybrid identities in response to institutional decline. Identity hybridization, we predict, takes place in stages via strategies that gradually hybridize the identity. We study how British political parties hybridized their identities in response to the decline of social-class politics over the period 1950-2015. Quantitative and qualitative analyses of the identity projections of three political parties in their election manifestos provide support for our hypotheses.

Many companies are now targeting the sizeable segment of consumers in Bottom-of-the-pyramid (BoP) markets with new products to specifically address their needs. As mainstream consumers become aware of these initiatives, their views on what products may be construed as appropriate for BoP marketplaces, may influence their attitudes towards the companies engaging in BoP activities. We propose that when the mainstream consumers are culturally distant from the BoP consumers, they have less favourable attitudes towards a company marketing a hedonic product to BoP consumers, compared to a utilitarian one. However, when the mainstream consumers are culturally closer to the BoP consumers, they are less likely to react negatively to a company's marketing of a hedonic product compared to a utilitarian one. We theorize that these differences in evaluation are based on the mainstream consumers' expectations regarding the products a company would/should target towards BoP consumers. We also examine two company characteristics (country-of-origin and profit orientation) as contingency factors affecting the attitudes of culturally close mainstream consumers towards companies engaging in BoP practices. Across two studies, we find support for our hypotheses. This research adds to a new stream of scholarship that theorizes about the permissible consumption mindset of mainstream consumers. The research also provides guidance to marketing managers and communication experts to help build favourable company attitudes and minimize any mainstream negativity towards a company's marketing initiatives in the BoP domain.

This research finds evidence for a plural name advantage on brand attitude. Six studies, including two archival datasets with real market brands and four experiments using fictitious brands, show that brands with plural names (e.g., Dunkin' Donuts) are associated with more favorable brand attitude than brands with singular names (e.g., Dunkin' Donut). This plural brand name advantage is driven by perceptions of brand entitativity emerging from the collective reading of plural entities. However, the positive effect of plural brand names on brand attitude is attenuated in the case of premium brands. This research has practical implications for brand name strategy and makes a theoretical contribution by bringing attention to the under-researched space of morphology in brand name linguistics.