Mean–variance and mean–semivariance portfolio selection: a multivariate nonparametric approach

While univariate nonparametric estimation methods have been developed for estimating returns in mean-downside risk portfolio optimization, the problem of handling possible cross-correlations in a vector of asset returns has not been addressed in portfolio selection. We present a novel multivariate nonparametric portfolio optimization procedure using kernel-based estimators of the conditional mean and the conditional median. The method accounts for the covariance structure information from the full set of returns. We also provide two computational algorithms to implement the estimators. Via the analysis of 24 French stock market returns, we evaluate the in-sample and out-of-sample performance of both portfolio selection algorithms against optimal portfolios selected by classical and univariate nonparametric methods for three highly different time periods and different levels of expected return. By allowing for cross-correlations among returns, our results suggest that the proposed multivariate nonparametric method is a useful extension of standard univariate nonparametric portfolio selection approaches.     

Accelerators as start-up infrastructure for entrepreneurial clusters

ABSTRACT

Infrastructure is commonly conceptualized as a set of facilities that play a critical role in facilitating activities by individuals and organizations. Conventionally, infrastructure is tightly linked to publicly funded projects that facilitate access to key resources and enable diverse activities. Within entrepreneurial clusters research, infrastructure includes universities, research institutions and telecommunication technologies that facilitate entrepreneurial activities. These capital-intensive investments seek to facilitate start-ups emergence by aiding access to markets and development of ideas. Accelerators facilitate the same activities and have only recently been conceptualized as start-up infrastructure. This study builds upon this research stream by elaborating on how accelerators can play this meaningful role at the cluster level. Specifically, and by relying on the analysis of empirical evidence from three distinct studies, we uncover how accelerators provide tangible and intangible dimensions of start-up infrastructure to form a positively reinforcing cycle of entrepreneurial activities. Additionally, our findings allow us to push further the idea that start-up infrastructure development can be an endogenous process involving multiple actors within the cluster. Our empirical findings and the theoretical insights derived from them have meaningful implications for the aforementioned literature, as well as start-up practitioners and policymakers linked to the funding of entrepreneurial clusters.     

Integrating Environmental,Social and Governance (ESG) Disclosure for a Sustainable Development: An Australian Study

Addressing environmental, social and governance (ESG) issues has become a critical part of business strategy. This article explores the extent of ESG reporting of metal and mining sector companies listed in the Australian Securities Exchange to determine the nature of ESG indicators in use in the sector. The current study argues that stakeholder engagement is the key to enhance company environmental policy and sustainable development. According to the results of this study, ESG reporting motives are highly influenced by reporting regulations. Given the diversity in reporting of ESG, comparability of ESG strategic performance is problematic. This study contributes towards developing an ESG disclosure index, which companies could use as a legitimacy tool that external stakeholders could use to reliably measure and compare the ESG performance of companies. It also reveals there is an increased demand for more empirical research on integration of sustainability into strategic planning process. Copyright © 2016 John Wiley & Sons, Ltd and ERP Environment     

Testing the Influence of Substitute Sites in Nature Valuation by Using Spatial Discounting Factors

This paper investigates the effect of nearby nature substitute sites on preferences for nature restoration. Contrary to prior studies, we use a respondent-centric approach to control for substitute sites. We assess each respondent-specific spatial context by computing densities of nature substitute sites within various ranges from each respondent’s home. This approach considers the use and non-use values of nature together. Data from three similar discrete choice experiments carried out in Flanders (Belgium) are compared. Different spatial discounting factors are tested to explore how the substitution effect behaves with regard to distance. Latent class analyses are performed to account for preference heterogeneity among respondents. We observe divergent behaviours across groups of respondents. The “distance-to-substitutes” affects how respondents gauge substitute sites. We find a significant influence of the squared average buffer distance but this effect varies in sign across case studies and classes of respondents. Our results demonstrate that individual-specific GIS data can significantly improve the representation of the spatial context and the transferability of value functions. However, the roles played by preference heterogeneity and nature perception on respondents’ capacity to value nature still deserves further attention in future research.     

Life Expectancy Heterogeneity and the Political Support for Collective Annuities

Individuals, differing in productivity and life expectancy, vote over the size and type of a collective annuity. Its type is represented by the fraction of the contributive (Bismarckian) component (based on the worker's past earnings) as opposed to the non‐contributive (Beveridgean) part (based on average contribution). The equilibrium collective annuity is either a large mostly Bismarckian program, a smaller pure Beveridgean one (in accordance with empirical evidence), or nil. A larger correlation between longevity and productivity, or a larger average life expectancy, both make the equilibrium collective annuity program more Beveridgean, although at the expense of its size.     

On Some Characteristics of Gaussian Covariance Functions

The concepts of isotropy/anisotropy and separability/non‐separability of a covariance function are strictly related. If a covariance function is separable, it cannot be isotropic or geometrically anisotropic, except for the Gaussian covariance function, which is the only model both separable and isotropic. In this paper, some interesting results concerning the Gaussian covariance model and its properties related to isotropy and separability are given, and moreover, some examples are provided. Finally, a discussion on asymmetric models, with Gaussian marginals, is furnished and the strictly positive definiteness condition is discussed.     

Could lean practices and process innovation enhance supply chain sustainability of small and medium‐sized enterprises?

Small and medium‐sized enterprises (SMEs) adopt lean practices (LP) to reduce waste across their organisational value chain, which helps achieve sustainability. Process innovation (PI) has also been applied through cleaner production, environmental management system, ecodesign, and so on to address both customers' needs and legislations by policymakers. Although prior studies reveal the effect of sustainable practices, LP, and PI on sustainable performance separately, less is known on the integrated effect of them on sustainability performance. Moreover, studies on mediating effect of LP and PI on sustainability performance are scant. This is significant as LP and PI are considered to be the enablers for achieving sustainability performance. This research addresses this knowledge gap. The research first theorises a model integrating these four major constructs (sustainability practices, LP, PI, and sustainability performance) through hypotheses development. Subsequently, using structural equation modelling, it is tested whether each of sustainability practices, LP, and PI effect sustainability performances. Additionally, mediating effect of LP and PI between sustainability practices and performances is derived. The study uses data from 119 SMEs within manufacturing industries in the Midlands, United Kingdom. Further, a few case studies have been undertaken to validate the findings from quantitative analysis. The overall results show that although sustainability practices, LP, and PI help achieve sustainability performance of SMEs supply chain through efficiency and responsiveness respectively, the mediating effect LP is more compared with PI. Moreover, SMEs adopt LP when they are economy focused and implement PI when they are pressurised by customers and/or policymakers.     

A Note on Family Influence and the Adoption of Discontinuous Technologies in Family Firms

The 4Cs model of command, continuity, community, and connections is useful for examining the effect of family influence on the adoption of discontinuous technologies. However, assuming that family influence differs only in degree rather than kind is naive because such an assumption ignores the likelihood of heterogeneous behaviors among family firms. In this conceptual note, we extend prior work and explain how heterogeneity in the family's relative emphasis on command, continuity, community, and connections requires that the multifaceted and potentially nonlinear nature of family influence be considered when analyzing strategic decisions concerning family firm innovation.     

Digital Transformation Through Exploratory and Exploitative Internet of Things Innovations: The Impact of Family Management and Technological Diversification*

This study examines the impact of family management on digital transformation with specific regard to the firm’s development of Internet of Things (IoT) innovations. Drawing on the distinctive characteristics of firms with family managers, such as the focus on family‐centered noneconomic goals, long tenure, emotional ties to existing assets, and rigid mental models, it hypothesizes that increasing family involvement in the top management team is negatively related to the development of IoT innovations that are distant from a firm’s existing technology base (i.e., exploratory IoT innovations) compared to exploitative IoT innovations. Further, the study proposes that the firm’s degree of technological diversification, especially in unrelated forms, reinforces this relationship. The longitudinal analysis between 2002 and 2013 on a sample of publicly traded German firms allows us to test our hypotheses from the beginning of the emergence of the IoT concept. Our findings show that due to the particular characteristics of their managers, family‐managed firms do not welcome the risks related to exploratory IoT innovations, and the benefit of risk diversification from technological diversification is lower than the cost of abandoning family‐centered goals. As our results imply that the involvement of family managers constrains the development of exploratory IoT innovation, the top management team composition in firms that intend to be at the forefront of the digital transformation should be accurately designed by avoiding a high proportion of family members.