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.     

Reversible Environmental Catastrophes with Disconnected Generations

De Economist - We study environmental policy in a stylized economy–ecology model featuring multiple deterministic stable steady-state ecological equilibria. The economy–ecology does not...     

Inflation and the Exchange Rate: The Role of Aggregate Demand Elasticity

This paper examines the effect of aggregate demand elasticity on the exchange rate when inflation occurs. We discover that both the source of the inflation, whether demand-pull or cost-push, and the elasticity of aggregate demand with respect to the price level, are of consequence for the exchange rate. We obtain two primary conclusions. First, the effect on the exchange rate of cost push inflation is ambiguous and is partially determined by the price level elasticity of aggregate demand. In particular, and assuming that the two examined countries have equivalent aggregate supply elasticities, we conclude that the nation with the less elastic aggregate demand function will see its currency appreciate relative to the other. Second, demand-pull inflation results in an unambiguous increase in the exchange rate but the size of that increase is partially a function of aggregate demand elasticity. Assuming again that two countries have equivalent aggregate supply elasticities, that country with the more elastic aggregate demand will experience currency appreciation.     

Saddlepoint approximations to the mean and variance of the extended hypergeometric distribution

Conditional inference on 2 x 2 tables with fixed margins and unequal probabilities is based on the extended hypergeometric distribution. If the support of the distribution is large, exact calculation of the conditional mean and variance of the table entry may be computationally demanding. This paper proposes a single‐saddlepoint approximation to the mean and variance. While the approximation achieves acceptable accuracy for ordinary practical purposes, an alternative saddlepoint approximation is provided that gives much closer to exact results. It improves the accuracy of current approximations to up to more than four powers of ten.     

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.     

Exploring consumer attitudes to online collaborative consumption: A typology of collaborative consumer profiles

Online collaborative consumption enhances peer networks, members of which communicate, collaborate, and even deliver services to one another via digital sharing platforms. Despite the tremendous increase in collaborative consumption, due in large part to the development of the Internet, the reality of the economic and social movements that underpin this trend is much less visible. Of course, not all consumers seek collaborative consumption or interact through online platforms. Using a qualitative approach, this paper aims to investigate motivational factors and barriers against collaborative consumption and to establish a typology of collaborative consumer profiles, identifying the most suitable type of online sharing platforms for each profile. The findings reveal the following collaborative consumer profiles: committed, pragmatists, intermittent, and skeptical, each demonstrating different preferences for the different type of online sharing platform.     

Different forms of corporate philanthropy,different effects: A multilevel analysis

This study investigates how different types of corporate philanthropy impact employees' life satisfaction. Grounded in signaling theory, we explore and clarify the nuances among three types of corporate philanthropy values: the absolute value of corporate philanthropy, the value of a firm's corporate philanthropy relative to its past level, and the value of corporate philanthropy relative to the firm size. Results of multilevel analyses on a large scale sample with 218 firms and 2,261 employees at two time points reveal that: the absolute value of corporate philanthropy positively influences employees' life satisfaction; the value of a firm's corporate philanthropy relative to its past philanthropy negatively impacts employees’ life satisfaction; and the value of corporate philanthropy relative to the firm size positively affects employees' life satisfaction. The results indicate that the influences of corporate philanthropy on employees' life satisfaction vary depending on the evaluation benchmarks. Firms may benefit by taking their size and past philanthropy into consideration when making corporate philanthropy investment decisions.     

Marx 200: The Abiding Relevance of the Labour Theory of Value

ABSTRACT

Marxist political economy is alive and well, and not just because of the habitual turn to Marx in response to any crisis of capitalism. Both through Capital and through the continuing evolution of Marxism, Marxist political economy offers valuable insights that can illuminate the modalities of social and economic reproduction and the relationships between (different aspects of) the economic and the non-economic. Marxism’s presence has been felt through its own internal debates and debates with other approaches to political economy, and even through its influence on those reacting against Marxism. The key to the continuing relevance and analytical strengths of Marxist political economy lies in its capacity to provide a framework of analysis for unifying disparate insights into and critiques of the contradictions of capitalism across the social sciences. The instrument for forging that unity is Marx’s theory of value, the potential of which is examined and illustrated with reference to the Sraffian critique and two key concepts in Marxian political economy: the value of labour power and financialisation. They are explored in the light of the processes of commodification, commodity form and commodity calculation.