Revisiting the outsourcing debate: two sides of the same story

Although outsourcing of organisational functions has become a popular practice amongst organisations, the literature provides a myopic and simplistic view of the phenomenon by focusing on either single functions or taking monadic views of a single party. The design of our study overcomes these weaknesses by including the following features: a range of organisational functions were included; the unit of analysis was the outsourcing contract; the level of analysis was at the dyadic level where both service providers and receivers presented their views and the approach was a qualitative one. In practice, this involved interviews with managers in service receiving and providing organisations that were in charge of 10 separate outsourcing arrangements. Using agency theory as a theoretical anchor, we contribute to the outsourcing debate by highlighting its complexity and areas of convergence and divergence between service receivers and providers, thereby suggesting a contingent approach towards implementation of outsourcing arrangements.     

On Power Approximations and Comparison of Several Asymptotic Tests to Detect a Specified Difference between Two Proportions

A large sample test is proposed for a problem of testing for a specified difference between two binomial proportions. The test is compared to the tests by Falk and Koch (1998 Falk , R. W. , Koch , G. G. ( 1998 ). Testing a specified difference between proportions . Biometrics 54 ( 4 ): 1602 – 1614 .[Crossref] , [Google Scholar]), and Parmet and Schechtman (2007 Parmet , Y. , Schechtman , E. ( 2007 ). On a test of the difference between two binomial proportions . Communications in Statistics – Theory and Methods 36 : 887 – 895 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]), and is shown to dominate in terms of the Type I error rate control. Asymptotic power is derived for each test and is shown to result in values quite proximate to the simulated power values. In addition, formulas to perform sample size estimation are provided. These methods are expected to be especially valuable in the design stage when obtaining the correct power/sample size estimation is essential.     

Evaluation of international corruption indexes: Should we believe them or not?

In this paper, we employ, and test the reliability and validity, of multiple corruption related datasets such as the Corruption Perceptions Index of Transparency International, the Control of Corruption Index of the World Bank, the International Country Risk Guide of PRS, the World Value Survey, the Bribe Payers Index, and the International Crime Victimization Survey. We find evidence that the reliability of international corruption indexes has improved over the years. However, a number of shortcomings – such as the risk of selection bias, longitudinal sensitivity, and measurement errors that are inherent in composite indexes – are commonly observed. These problems are critical enough to affect the results of empirical analysis, as we illustrate using linear models. Therefore, we conclude that researchers should pay more attention towards minimizing the impact of measurement error through rigorous data screening and robustness tests using multiple data sources and methods. A thorough and systematic evaluation of the reliability and validity of international corruption indexes is essential to increase their usefulness.     

From theory to practice: maximizing revenues for on-line dial-a-ride

We consider the on-line dial-a-ride problem, where a server fulfills requests that arrive over time. Each request has a source, destination, and release time. We study a variation of this problem where each request also has a revenue that the server earns for fulfilling the request. The goal is to serve requests within a time limit while maximizing the total revenue. We first prove that no deterministic online algorithm can be competitive unless the input graph is complete and edge weights are unit. We therefore focus on these graphs and present a 2-competitive algorithm for this problem. We also consider two variations of this problem: (1) the input graph is complete bipartite and (2) there is a single node that is the source for every request, and present a 1-competitive algorithm for the former and an optimal algorithm for the latter. We also provide experimental results for the complete and complete bipartite graphs. Our simulations support our theoretical findings and demonstrate that our algorithms perform well under settings that reflect realistic dial-a-ride systems.     

Application of Anbar's Approach to Hypothesis Testing to Detect the Difference between Two Proportions

In this paper, Anbar's (1983) approach for estimating a difference between two binomial proportions is discussed with respect to a hypothesis testing problem. Such an approach results in two possible testing strategies. While the results of the tests are expected to agree for a large sample size when two proportions are equal, the tests are shown to perform quite differently in terms of their probabilities of a Type I error for selected sample sizes. Moreover, the tests can lead to different conclusions, which is illustrated via a simple example; and the probability of such cases can be relatively large. In an attempt to improve the tests while preserving their relative simplicity feature, a modified test is proposed. The performance of this test and a conventional test based on normal approximation is assessed. It is shown that the modified Anbar's test better controls the probability of a Type I error for moderate sample sizes.     

Robustly assigning unstable items

Journal of Combinatorial Optimization - We study the robust assignment problem where the goal is to assign items of various types to containers without exceeding container capacity. We seek an...