Technical innovation and 3.5 mobile phone generation: Lessons from Korea

In 1996, the Korean mobile communication market was the first in the world to commercialize the code division multiple access (CDMA). Since then, the voice-based mobile phone market has continued to grow and has now reached near saturation. Having recognized the potential of the mobile data service as a new source of profit, telecommunication operators are scrambling to evolve 3.5 generation (3.5G) technology in order to lead market competition. Recently, the Korean 3.5G mobile telecom market has faced stiff competition from CDMA-based EVDO Rev.A and global system for mobile telecommunications (GSM)-based high-speed downlink packet access (HSDPA). In addition, the world's first wireless LAN-based wireless broadband internet (WiBro) service was commercialized in June, 2006. This paper reviews the current status of the 3.5G technology and analyzes the service standardization strategies from the viewpoint of technological evolutions. This paper also suggests implications for Korea's specific circumstances where different mobile telecom technologies complement and compete with one another. Korea's experiences may serve as important lessons for other countries or operators who try to introduce the 3G and look beyond mobile telecom technologies.     

Emotional and interpersonal competencies and leader development

A variety of recent leader development programs have focused on improving leaders' emotional and interpersonal competencies. Decades of leadership research suggest that these “people skills” are crucial for leader effectiveness. This paper reviews the history of these leader development programs as well as research on emotional and interpersonal competencies. Suggestions for grounding leader development programs in sound research on emotional and social competencies, as well as an agenda for future research on the development of leader emotional and interpersonal skills, are provided.     

Are Expected Inflation Rates and Expected Real Rates Negatively Correlated? A Long‐Run Test of the Mundell‐Tobin Hypothesis

Some empirical evidence suggests that the expected real interest and expected inflation rates are negatively correlated. This hypothesis of negative correlation is sometimes known as the Mundell‐Tobin hypothesis. In this article we reinvestigate this negative relation from a long‐term point of view using cointegration analysis. The data on the historical interest rate on T‐bills and the inflation rate indicate that the Mundell‐Tobin hypothesis does not hold in the long run for the United States, the United Kingdom, and Canada. We also obtain similar results using the real interest rate on index‐linked gilt traded in the United Kingdom.     

Theoretical considerations for a meaningful code of professional ethics

The professions have focused considerable attention on developing codes of conduct. Despite their efforts there is considerable controversy regarding the propriety of professional codes of ethics. Many provisions of professional codes seem to exacerbate disputes between the profession and the public rather than providing a framework that satisfies the public's desire for moral behavior.After examining three professional codes, we divide the provisions of professional codes into those provisions which urge professionals to avoid moral hazard, maintain professional courtesy and serve the public interest. We note that whereas provisions urging the avoidance of moral hazard are uncontroversial, the public is suspicious of provisions protecting professional courtesy. Public interest provisions are controversial when the public and the profession disagree as to what is in the public interest. Based on these observations, we conclude with recommendations regarding the content of professional codes.Karim Jamal is an Associate Professor in the Department of Accounting at the University of Alberta. His research interests are in modelling judgment processes of individuals in professional firms and financial markets. He is currently involved in research on the auditor-client negotiation process, the role of framing effects in masking fraud as well as the means by which frauds are detected, and tensions in professional codes of conduct especially between confidentiality and public disclosure.Norman E. Bowie is the Elmer L. Andersen Chair in Corporate Responsibility at the University of Minnesota. He is the co-editor ofEthical Theory and Business and has published numerous books and articles in business ethics and political philosophy. His most recent book isUniversity Business Partnerships: An Assessment.     

An appreciation of our referees

Editorial

An appreciation of our referees     

Evaluation of dynamic stochastic general equilibrium models based on distributional comparison of simulated and historical data

We take as a starting point the existence of a joint distribution implied by different dynamic stochastic general equilibrium (DSGE) models, all of which are potentially misspecified. Our objective is to compare “true” joint distributions with ones generated by given DSGEs. This is accomplished via comparison of the empirical joint distributions (or confidence intervals) of historical and simulated time series. The tool draws on recent advances in the theory of the bootstrap, Kolmogorov type testing, and other work on the evaluation of DSGEs, aimed at comparing the second order properties of historical and simulated time series. We begin by fixing a given model as the “benchmark” model, against which all “alternative” models are to be compared. We then test whether at least one of the alternative models provides a more “accurate” approximation to the true cumulative distribution than does the benchmark model, where accuracy is measured in terms of distributional square error. Bootstrap critical values are discussed, and an illustrative example is given, in which it is shown that alternative versions of a standard DSGE model in which calibrated parameters are allowed to vary slightly perform equally well. On the other hand, there are stark differences between models when the shocks driving the models are assigned non-plausible variances and/or distributional assumptions.     

Forecasting economic time series using flexible versus fixed specification and linear versus nonlinear econometric models

Nine macroeconomic variables are forecast in a real-time scenario using a variety of flexible specification, fixed specification, linear, and nonlinear econometric models. All models are allowed to evolve through time, and our analysis focuses on model selection and performance. In the context of real-time forecasts, flexible specification models (including linear autoregressive models with exogenous variables and nonlinear artificial neural networks) appear to offer a useful and viable alternative to less flexible fixed specification linear models for a subset of the economic variables which we examine, particularly at forecast horizons greater than 1-step ahead. We speculate that one reason for this result is that the economy is evolving (rather slowly) over time. This feature cannot easily be captured by fixed specification linear models, however, and manifests itself in the form of evolving coefficient estimates. We also provide additional evidence supporting the claim that models which ‘win’ based on one model selection criterion (say a squared error measure) do not necessarily win when an alternative selection criterion is used (say a confusion rate measure), thus highlighting the importance of the particular cost function which is used by forecasters and ‘end-users’ to evaluate their models. A wide variety of different model selection criteria and statistical tests are used to illustrate our findings.