Optimal requirement allocation among quantity-discount quoting suppliers

We consider a problem motivated by a central purchasing organization for a major office products distributor. This purchasing organization must source a quantity of a particular resale item from a set of capacitated suppliers. In our case each supplier offers an incremental quantity discount purchase price structure. The purchaser’s objective is to obtain a quantity of a required item at minimum cost. The resulting problem is one of allocating order quantities among an approved supply base and involves minimizing the sum of separable piecewise linear concave cost functions. We develop a branch and bound algorithm that arrives at an optimal solution by generating linear knapsack subproblems with feasible solutions to the original problem. This research was partially supported by a 2007 Summer Research Grant awarded to Asoo J. Vakharia.     

Participatory planning of industrial R&D activities

This paper summarizes and comments on the methodology actually employed in participatory planning of R&D activities for the iron and steel industry in Turkey. Through an organized collaboration with more than a hundred managers, engineers, experts, and planners: (1) technical, managerial, financial, and social problems that are obstacles to the achievement of predetermined goals for the industry are identified and defined; (2) these problems are formulated as R&D candidate projects; and (3) a set of R&D candidate projects are selected for implementation in the 1980s.     

Security in a sea of insecurity: job security and intention to stay among service sector employees in Turkey

This article examines the association between job security and intention to stay for those who are employed in Turkey. There is a high level of unemployment in the country and many workers there are concerned about their job security. Job security refers to the objective dimensions of continuous contract, working full-time hours and paid and unpaid overtime. Job security also refers to the subjective dimension of perceived job security. We surveyed 407 employees in banking and related sectors' call centres, five-star hotel front-line staff and airline cabin crews. Results show that objective dimensions of job security are not associated with intention to stay. However, perceived job security is significantly and positively associated with intention to stay. We recommend that human resource managers focus on the perceived job security aspect of employment to keep valuable employees with the company.     

An Analogy Explanation for the Evaluation of Entrepreneurial Opportunities

Entrepreneurs evaluate opportunities under conditions of uncertainty; they make judgments. To understand these evaluations, I develop an analogical model that represents an entrepreneurial opportunity in the mind of an individual. The model proposes that an opportunity is an analogical knowledge transfer from a source business domain to a target business domain. According to the model, the cognitive distance between the domains influences the opportunity evaluation. Additionally, the inspiration behind the analogy construction influences the opportunity evaluation. The empirical design employs a hypothetical scenario experiment and the results show that the two analogical properties matter for evaluation.     

Exploring the Diversity of Virtues Through the Lens of Moral Imagination: A Qualitative Inquiry into Organizational Virtues in the Turkish Context

The purpose of this article is to introduce a multidimensional framework based on the concept of moral imagination for analysing and capturing diverse virtues in contemporary Turkish organizations. Based on qualitative interviews with 58 managers in Turkey, this article develops an inventory of Turkish organizational virtues each of which can be associated with a different form of virtuous organizing. The inventory consists of nine forms of moral imagination, which map the multitude of virtues and moral emotions in organizations. Nine emergent forms of moral imagination are based on: integrity, affection, diligence, inspiration, wisdom, trust, gratefulness, justice, and harmony. The findings have made a contribution to the expanding literature on how Islamic organizations develop their business ethics through a repertoire of virtues. An empirical account of the range of virtues in organizational contexts that have emerged as a result of the hybridization of Islamic virtue/aesthetics and neoliberal capitalism in contemporary Turkey is provided. A theoretical contribution is made to business ethics literature through a phenomenology of virtues that provides unique insights on diverse forms of moral imagination in contemporary Turkey where Islam and neoliberal capitalism dynamically co-exist.     

The Islamic Work Ethic and the Emergence of Turkish SME Owner-Managers

The aim of this study is to explore the influence of religious beliefs on the work-related attitudes of Turkish SME (small and medium-sized enterprise) owner-managers. In this research, the emergence of pious or devout business people is considered as a phenomenon, and special attention is paid to religious transformation and secularism in Turkey. Both concepts, religion and secularism, are considered within the Turkish context. For the research, in-depth interviews were conducted with 32 Turkish business people from religious and secular backgrounds, respectively. The study investigates the so-called “Islamic work ethic” values and Islamic business principles from a critical perspective and argues that they do not seem to be as significant factors as predicted in the emergence of pious or devout business people in Turkey.     

An exploratory study on the perspectives of prospective computer teachers following project-based learning

This study investigates perceptions of 29 prospective teachers about a course based on Project-Based Learning (PBL) approach. The course, ‘Authoring Languages in PC Environment (B-320)’ lasted in 14 weeks in fall semester of 2004–2005. In this course each prospective teacher carried out a project that requires designing and developing courseware individually. This study is qualitative in nature and data were collected through an open ended questionnaire composed of seven items and analyzed by content analysis technique. The results show that prospective teachers found PBL as an effective way of learning. It also suggests that when efficient guidance about technical issues and time management is provided, PBL approach can be successfully implemented in computer related courses such as programming language and web designing.     

Multi-player bargaining with endogenous capacity

We study equilibrium prices and trade volume in a market with several identical buyers and a seller who commits to an inventory and then offers goods sequentially. Prices are determined by a strategic costly bargaining process with a random sequence of proponents. A unique subgame perfect equilibrium exists, characterized by no costly delays and heterogeneous sale prices. In equilibrium constraining capacity is a bargaining tactic the seller uses to improve a weak bargaining position. With capacity constraints, sale prices approach the outcome of an auction as bargaining costs vanish. The framework provides a building block for price formation in models of equilibrium search with multilateral matching, and offers a rationale for the adoption of single-unit auctions with fixed reservation price.     

Nonparametric tests for Optimal Predictive Ability

A nonparametric method for comparing multiple forecast models is developed and implemented. The hypothesis of Optimal Predictive Ability generalizes the Superior Predictive Ability hypothesis from a single given loss function to an entire class of loss functions. Distinction is drawn between General Loss functions, Convex Loss functions, and Symmetric Convex Loss functions. The research hypothesis is formulated in terms of moment inequality conditions. The empirical moment conditions are reduced to an exact and finite system of linear inequalities based on piecewise-linear loss functions. The hypothesis can be tested in a statistically consistent way using a blockwise Empirical Likelihood Ratio test statistic. A computationally feasible test procedure computes the test statistic using Convex Optimization methods, and estimates conservative, data-dependent critical values using a majorizing chi-square limit distribution and a moment selection method. An empirical application to inflation forecasting reveals that a very large majority of thousands of forecast models are redundant, leaving predominantly Phillips Curve-type models, when convexity and symmetry are assumed.