Hope and positive affect mediating the authentic leadership and creativity relationship

The study analyzes how authentic leadership (AL) predicts employees' creativity both directly and through the mediating role of employees' positive affect and hope. Two hundred and three employees working in Portuguese retail organizations participate in the research. Employees report their hope and positive affective states, as well as the AL of their supervisors. Supervisors report the employees' creativity. The main findings are: (a) AL predicts employees' creativity, both directly and through the mediating role of employees' hope; (b) AL also predicts employees' positive affect, which in turn predicts employees' hope and, thus, creativity. The study enriches the understanding of the processes through which AL improves employees' creativity, and provides valuable insights for both scholars and practitioners. By promoting AL, and employees' hope and positive affect, organizations may increase employees' creative performance, creativity being an important path to organizational performance.     

An improved algorithm and solution on an integrated production-inventory model in a three-layer supply chain

Ben-Daya et al. (2010) established a joint economic lot-sizing problem (JELP) for a three-layer supply chain with one supplier, one manufacturer, and multiple retailers, and then proposed a heuristic algorithm to obtain the integral values of four discrete variables in the JELP. In this paper, we first complement some shortcomings in Ben-Daya et al. (2010), and then propose a simpler improved alternative algorithm to obtain the four integral decision variables. The proposed algorithm provides not only less CPU time but also less total cost to operate than the algorithm by Ben-Daya et al. (2010). Furthermore, our proposed algorithm can solve certain problems, which cannot be solved by theirs. Finally, the solution obtained by the proposed algorithm is indeed a global optimal solution in each of all instances tested.     

Estimation of conditional time-homogeneous credit quality transition matrices

This paper presents a methodology for estimating time-homogeneous credit quality transition matrices. Using a unique data set on credit ratings of commercial loans in Colombia, we show that 70% of the time we cannot reject the null hypothesis of time homogeneity of transition matrices estimated this way. We also find that obtaining matrices for different subsamples is not necessary, given the similarities of the survival functions.     

TV white spaces exploitation through a bicameral geo-location database

The exploitation of TV white spaces can meet the increasing demand for spectrum resources and create opportunities for deploying a variety of wireless services in a flexible manner. However, uncertainties from technologies, business models and regulatory policies hinder the take-off of TV white spaces exploitation. This paper proposes a bicameral (or two-chambered) geo-location database, which allows/supports both free and paid access to the TV white spaces: i.e., one chamber supports free access through opportunistic or geo-location database access; and the other chamber supports paid usage through secondary spectrum trading. Consequently, four technological scenarios for the acquisition of TV white spaces emerge, namely: sensing only, joint sensing and geo-location database access, geo-location database access only, and broker based secondary spectrum trading. An analysis of these scenarios is performed based on a theoretical framework for emerging technology evaluation while considering technological, business models and regulatory dimensions. The analyses show that free and paid access to TV white space complement each other; and that despite considerable infrastructure costs, the bicameral geo-location database is positioned to create viable TV white spaces exploitation value chains; hence have the most optimal technological, business and regulatory prospects.     

Privatizing Highways in the United States

We review the experience of both private toll-roads built in the United States during the 1990s, and argue that the problems they encountered could have been avoided if the length of the franchise contract would adapt to demand realizations. We also argue in favor of adjudicating private toll-roads via BOT-type contracts in competitive (Demsetz) auctions. The lessons of this paper are relevant since growing congestion and troubled government finances have made private toll-roads increasingly attractive in the United States.