An extension to the classical mean–variance portfolio optimization model

Abstract

The purpose of this study is to find a portfolio that maximizes the risk-adjusted returns subject to constraints frequently faced during portfolio management by extending the classical Markowitz mean–variance portfolio optimization model. We propose a new two-step heuristic approach, GRASP & SOLVER, that evaluates the desirability of an asset by combining several properties about it into a single parameter. Using a real-life data set, we conduct a simulation study to compare our solution to a benchmark (S&P 500 index). We find that our method generates solutions satisfying nearly all of the constraints within reasonable computational time (under an hour), at the expense of a 13% reduction in the annual return of the portfolio, highlighting the effect of introducing these practice-based constraints.     

Tecnología,deslocalización y tareas definitorias de las ocupaciones en el Reino Unido

Los autores analizan los cambios de las tareas definitorias (margen intensivo) y de los niveles de empleo (margen extensivo) de las ocupaciones en el Reino Unido de 1997 a 2006 con datos de la Encuesta nacional sobre calificaciones (Skills Survey). Encuentran que las tareas definitorias de las ocupaciones cambiaron significativamente, y que la magnitud del cambio fue similar a la encontrada en el margen extensivo. Según sus resultados econométricos, este cambio de las tareas definitorias puede explicarse por los avances tecnológicos, pero no por la deslocalización.     

Complexity of Socio-spatial Transformations Through Tourism: A Mediterranean Village,Kaleköy

This article reflects on the complex consequences of tourism development in the isolated Mediterranean village of Kaleko¨y. Built on the antique city of Simena of the 4th century BC and having remnants also from Hellenistic, Byzantine and Ottoman periods, Kaleköy's main source of livelihood since the 1980s has been tourism. Multiple changes that take place simultaneously at the local level, in relation to or as a consequence of tourism, are conceptualised as interrelated transformations that may fall under the four major headings of economy, demography, spatial organisation and cognition. Defining culture as 'everything learned', these transformations amount to a radical change in the local culture, which now includes a culture of tourism. Based on ethnographic research, the article aims to demonstrate the complexity of changes in physical, as well as economic and social structures as they pertain to tourism.     

Globalization and flattening of Phillips Curve in Turkey between 1987 and 2007

In the last two decades, there have been important changes in inflation dynamics in Turkey. While average inflation rate, inflation volatility and inflation persistence declined, the prices of tradable goods have shown an increase less than prices of non-tradable goods. The aim of this paper is to inquire whether the globalization has an effect on this change and to test whether and how it affected the slope of the Phillips Curve. The findings point out that global activity did have an effect on domestic inflation rate and that Phillips Curve got flatter.     

Food safety attitudes and practices of chefs in Cappadocia region,Turkey

ABSTRACT

Chefs working at hotels, restaurants, and public institutions play a major role in food safety. The aim of this study is to explore attitudes and practices regarding food safety issues among chefs in the Cappadocia region, Turkey. The data was collected using a convenience sampling method of the non-probability sampling technique. The survey was conducted between the period of September 2018 and November 2018, and 108 chefs working at hotels, restaurants, and public institutions participated. The data were analyzed using frequencies, exploratory factor analysis, independent sample t-test, ANOVA, correlation, and simple linear regression analyses. Most of the chefs (79.6%) had taken a basic food safety training course. The findings reveal that there are statistically significant (p < .05) differences between groups: (a) demographics and attitudes, and (b) demographics and practices. The findings also show that there is a significant (p < .05) and positive correlation (r = 0.48) between the attitudes and practices of chefs. This study posits that food safety trained chefs have higher scores in terms of both attitudes and practices than those who have not received. It is recommended that all chefs should be encouraged to attend food safety training programs. Practical and academic implications are discussed in detail.     

Proposal for a Global Fund for Women through Innovative Finance

Despite the spread of budget initiatives for gender equality following the Beijing Declaration of 1995, resources allocated for eliminating gender inequalities remain inadequate. This paper proposes to create a Global Fund for Women through Innovative Finance (GFWIF) with the ability to raise funds through innovative sources of finance on a scale more appropriate to the estimated requirements of making reasonable progress toward gender equality (US$31–107 billion per year in constant 2014 dollars). It builds on previous calls by feminist economists for the establishment of such funds through global forms of taxation. Since donors’ commitments only meet the lower bound, the GFWIF could scale up funding for gender equality interventions commensurate with country needs. Global resource mobilization through innovative mechanisms, including allocations of new Special Drawing Rights, currency transaction taxes, and carbon taxes, have the potential to provide the necessary financing at a much faster pace than is currently possible.     

Western Canadian producers’ attitudes towards wheat breeding funding

In 2017, the federal government initiated national consultations for two new crop royalty systems that could be used to support additional crop breeding. In this study, we examine wheat growers’ attitudes towards breeding research and assess their inclination to contribute more to wheat variety development through checkoffs or enhanced royalties. We report a random effect probit estimation for a survey of 877 western Canadian wheat producers that took place from November 2018 to January 2019. We found at least 26% of survey respondents were willing to pay more to support additional wheat breeding. However, this support is contingent on the model for revenue collection and where additional revenue is invested. Producers generally favored increased checkoffs over enhanced royalty collection. Among the royalty options presented, the farm saved seed royalties mechanism had less support than the simpler to implement end-point royalties mechanism. We also found support is much higher if new royalty mechanisms are used to support university or government programs versus private breeding programs. This result suggests developing widespread producer support for enhanced royalty collection may require broader commitments for funding, ownership, and control of crop breeding programs.     

Technological progress and scientific indicators: a panel data analysis

Total factor productivity (TFP) is generally interpreted to be a proxy for technological advancement. In this paper, we use stochastic frontier analysis to decompose the growth in TFP into three components: technological progress, scale effect and change in technical efficiency. Then, we conduct a comprehensive panel data analysis using the technological progress component of the TFP growth and several scientific and technological indicators using data from 160 countries over the period from 1960 to 2009. Our results generally show that the technological progress component of the TFP growth properly reflects certain dimensions of actual scientific and technological progress. However, we also find that this result is somewhat sensitive to different econometric specifications and assumptions.     

Ad avoidance in the digital context: A systematic literature review and research agenda

The recent growth in digital marketing investments and revenues has attracted the attention of both marketing practitioners and scholars. However, this growth has dramatically increased users' exposure to ad messages, encouraging consumers to avoid them. Therefore, ad avoidance has become a major problem for marketing practitioners. Although researchers have become much more interested in this subject over the past two decades, the body of knowledge on ad avoidance in the digital environment remains fragmented due to the lack of a comprehensive review. Therefore, a holistic overview study is needed that focuses on the big picture and can help researchers to understand the literature comprehensively. This study aims to provide a comprehensive understanding of the topic using a systematic literature review approach on digital ad avoidance. To this end, we provide an in-depth content analysis of 56 relevant articles published in 31 peer-reviewed scientific journals up to December 31, 2021. Based on a theories, contexts, characteristics, and methods (TCCM) framework, the study results shed light on ‘what do we know, how do we know, and where should research about digital ad avoidance research be heading?’ Additionally, drawing on the content analysis, we have presented an integrative framework that considers antecedents, outcomes, mediators, and moderators, which can help develop the field systematically and guide future research. By doing so, we think this review meets the need to give an overview of the state-of-the-art scientific body of knowledge on digital ad avoidance and makes important and solid contributions to the literature, practical implications, and future research directions based on the findings.     

Return and volatility spillovers among CIVETS stock markets

Coined in 2009, the CIVETS refers to Colombia, Indonesia, Vietnam, Egypt, Turkey, and South Africa as a new group of frontier emerging markets with young and growing populations and dynamic economies. We provide a first look into the return and volatility spillovers between the CIVETS countries by employing causality-in-mean and causality-in-variance tests. The empirical results indicate that the contemporaneous spillover effects are generally low. Nevertheless, CIVETS stock markets may exhibit higher degrees of co-movements at times. The structure of the causal relationships further suggests the presence of intra-regional and inter-regional return and volatility interdependence effects.