Seasonal decomposition and forecasting of telecommunication data: A comparative case study

In this paper, forecasting models for the monthly outgoing telephone calls in a University Campus are presented. The data have been separated in the categories of international and national calls as well as calls to mobile phones. The total number of calls has also been analyzed. Three different methods, namely the Seasonal Decomposition, Exponential Smoothing Method and SARIMA Method, have been used. Forecasts with 95% confidence intervals were calculated for each method and compared with the actual data. The outcome of this work can be used to predict future demands for the telecommunications network of the University.     

Disagreement and Biases in Inflation Expectations

Disagreement in inflation expectations observed from survey data varies systematically over time in a way that reflects the level and variance of current inflation. This paper offers a simple explanation for these facts based on asymmetries in the forecasters' costs of over- and underpredicting inflation. Our model implies (i) biased forecasts, (ii) positive serial correlation in forecast errors, (iii) a cross-sectional dispersion that rises with the level and the variance of the inflation rate, and (iv) predictability of forecast errors at different horizons by means of the spread between the short- and long-term variance of inflation. We find empirically that these patterns are present in inflation forecasts from the Survey of Professional Forecasters. A constant bias component, not explained by asymmetric loss and rational expectations, is required to explain the shift in the sign of the bias observed for a substantial portion of forecasters around 1982.     

The value relevance and reliability of reported goodwill and identifiable intangible assets

We examine the value relevance and reliability of reported goodwill and identifiable intangible assets under Australian GAAP from 1994 to 2003; a period characterised by relatively restrictive accounting treatment for goodwill and relatively flexible accounting treatment for identifiable intangible assets. Our findings, using an adaptation of Feltham and Ohlson (1995), suggest that for the average Australian company the information presented with respect to both goodwill and identifiable intangible assets is value relevant but not reliable. In particular, goodwill tends to be reported conservatively while identifiable intangible assets are reported aggressively.     

The effect of general counsel prominence on the pricing of audit services

We investigate the effect of corporate general counsel (GC) ascension to the senior management team on the pricing of audit services. Prior research suggests that the GC position may have a significant influence in setting the tone at the top by promoting corporate integrity, ethics, and serving as a governance and monitoring mechanism, but also recognizes that prominent GCs may face ethical dilemmas, causing them to disregard professional responsibilities to curry the favor of the CEO and other executives. Using audit fees to proxy for audit engagement risk, we find a negative association between GC ascension to top management and audit fees. We investigate the mechanisms behind this relation and find GC ascension is associated with a reduction in both default risk and financial misstatement risk, which supports auditors’ perceived reduction in client business risk and audit risk, respectively.     

Why integrating purchasing with marketing is both inevitable and beneficial

The shift away from manufacturing in Western developed economies has resulted in economies in which service industries are dominant. Marketing itself has undergone a paradigmatic shift from a focus on the exchange of goods to the provision of capabilities. This paper examines the relationship between marketing and purchasing as a result of the shift from product- to capability-focused commerce. We suggest that the marketing and purchasing departments will become closer due to two major reasons. First, as marketers increasingly become solution-oriented rather than product-focused, they will need to source products and services from third-party vendors and will require deeper involvement of the purchasing department. Second, with the emergence of customer-centric marketing coupled with build-to-order manufacturing, marketing and purchasing will have to be better aligned to deliver solutions to customers. These new dimensions in the marketing–purchasing interaction will also lead to changes in the selection, training, and recruitment of marketers and purchasers as well as their roles in the supply chain. We elaborate on these changes likely to occur in business-to-business organizations and along with implications for managers.     

A synthesis of exact inferential results for exponential step-stress models and associated optimal accelerated life-tests

A reliability experimenter is often interested in studying the effects of extreme or varying stress factors such as load, pressure, temperature and voltage on the lifetimes of experimental units. Accelerated life-tests allow the experimenter to vary the levels of these stress factors in order to obtain information on the parameters of the lifetime distributions more rapidly than under normal operating conditions. Step-stress tests are a particular class of accelerated life-tests which allow the experimenter to change the stress levels at pre-fixed times during the life-testing experiment. One of the prominent models assumed in step-stress tests is the cumulative exposure model which connects the lifetime distribution of units at one stress level to the lifetime distributions at preceding stress levels. Under such a cumulative exposure model and the assumption that the lifetimes at different stress levels are exponentially distributed, we review in this article various developments on exact inferential methods for the model parameters based on different forms of censored data. We also describe the approximate confidence intervals based on the asymptotic properties of maximum likelihood estimators as well as the bootstrap confidence intervals, and provide some comparisons between these methods. Finally, we present some examples to illustrate all the inferential methods discussed here.     

Ranked set sampling and randomized response procedures for estimating the mean of a sensitive quantitative character

This paper is devoted to the analysis of the estimation of the mean of a sensitive variable. The use of a randomized response (RR) procedure gives confidence to the interviewed that his privacy is protected. We consider that a simple random sampling with replacement design is used for selecting a sample. The behavior of the RR procedure, when ranked set sampling is the design used, is developed under three different ranking criteria. The usual gain in accuracy associated with the use of ranked set sampling is exhibited only by one of the designs. The behavior of the models is illustrated using data provided by a study of samples of persons infected with AIDS.     

An automatic Portmanteau test for serial correlation

This article introduces a data-driven Box–Pierce test for serial correlation. The proposed test is very attractive compared to the existing ones. In particular, implementation of this test is extremely simple for two reasons: first, the researcher does not need to specify the order of the autocorrelation tested, since the test automatically chooses this number; second, its asymptotic null distribution is chi-square with one degree of freedom, so there is no need of using a bootstrap procedure to estimate the critical values. In addition, the test is robust to the presence of conditional heteroskedasticity of unknown form. Finally, the proposed test presents higher power in simulations than the existing ones for models commonly employed in empirical finance.     

Organizational form and environment: an analysis of between‐form and within‐form responses to environmental change

This study extends previous research on organizational adaptation to major environmental shifts by empirically examining the potential constraining effects of organizational form, operationalized using the Miles and Snow typology, on the type of responses enacted as well as the performance effects of the responses. Results indicate that a fit between environmental contingencies and organizational form relates to superior performance. The results also provide support for the idea that organizations systematically move toward the higher‐performing forms for a given environment. Consistent with organizational configuration logic, while these responses lead to performance improvements when a between‐form change is made, they do not necessarily lead to performance improvements when a within‐form change is made. Copyright © 2000 John Wiley & Sons, Ltd.