Estimating demand curve in the Korean VoIP telecommunications market

The VoIP (Voice over Internet Protocol) market in Korea is showing rapid growth since domestic carriers initiated the service in 2006. These carriers are now seeking new revenue sources from various convergence services and are increasing investment into VoIP. In particular, local exchange carriers (LECs), formerly reluctant to invest in technologies that would cannibalize their local telephone revenue, have started to invest in VoIP, in recognition of the current convergence of media and the telecommunications industry, as well as in the face of intensifying competition. In this study, we determined that VoIP call rates and landline telephony call rates were the most important factors affecting VoIP call demand, in addition to network externality. We also verified that landline telephony is no longer a supplement to VoIP, but rather, a substitute that has considerable influence on VoIP call demand. Empirical evidence is expected to be considered in policy decision making on current issues in the IT industry, such as access prices or competitiveness assessment. The current empirical analysis on the Korean VoIP industry and the adherence to lessons learned from policy enforcement should provide valuable information to countries seeking to develop their own VoIP industries, as well as to businesses developing new strategies based on the VoIP market.     

Technical change and total factor productivity growth: The case of Chinese provinces

In the literature technical change (TC) is mostly assumed to be exogenous and specified as a function of the time trend or time dummies. However, some exogenous external factors other than time can also affect TC. In this paper we model TC via time trend (external non-economic) as well as other exogenous (external economic) factors (technology shifters). For this we define technology indices based on the external economic factors and the time trend. The specification of production function is then amended to accommodate these technology indices which are not necessarily separable from the traditional inputs. That is, these technology indices allow for non-neutral shift in the production function. In doing so we are able to decompose TC (a component of TFP change) into two parts. One part is driven by time and the other part is related to producer-specific external economic factors. The latter can further be decomposed into each external economic factors. The empirical model uses panel data on Chinese provinces. We identify a number of key technology shifters and their effect on technical change and TFP growth of provinces are examined.     

Monitoring trends of technological changes based on the dynamic patent lattice: A modified formal concept analysis approach

The strategic importance of monitoring technological changes is highlighted given the ever faster pace and increasing complexity of technological innovation. In this respect, patent citation analysis has been the most frequently adopted tool among others. However, patent citation analysis is subject to certain drawbacks that stem from only consideration of citing-cited information and time lags between citing and cited patents. This study proposes a formal concept analysis (FCA)-based approach to developing a dynamic patent lattice that can analyze complex relations among patents and monitor trends of technological changes. The FCA is a mathematical tool for grouping objects with shared properties based on the lattice theory. The distinct strengths of FCA, vis-á-vis other methods, lie in structuring and displaying the relations among objects from a massive amount of data. For the purpose of technology monitoring, the FCA is modified to take into account time periods and changes of patent keywords. A patent context is first constructed with the aid of domain experts and text mining technique. Two types of dynamic patent lattices are then developed by executing the modified FCA algorithm. A case study of laser technology in lithography for semiconductor manufacturing shows that the suggested dynamic patent lattice has considerable advantages over conventional patent citation maps in terms of visualization and informative power.     

Model for evaluating the environmental sustainability of energy projects

This article focuses on the problem of assessing the environmental sustainability of energy projects. For this purpose an original model, which is based on various indicators that measure the environmental sustainability of energy projects, has been developed. This model, so called index of environmental sustainability of energy projects (IESEP), can be used in scenario comparison, while measuring the effectiveness of the proposed alternatives. Finally, an example of how to use this model is provided by analyzing alternatives to ameliorate the environmental sustainability of a hydroelectric project. In doing so, it is possible to show the usefulness of this model when used as a decision making tool for energy planners.     

Forecasting of electricity costs based on an enhanced gray-based learning model: A case study of renewable energy in Taiwan

This work presents a novel gray-based cost efficiency (GCE) model that integrates the gray forecasting model into a two-factor cost efficiency curve model for renewable energy (RE) technologies and identifies the optimal forecasting model for power generation cost of RE technologies. The analytical framework of proposed GCE model improves short-term prediction of power generation cost, and can be applied during the early developmental stages for RE technologies. Empirical analysis is based on wind power data for Taiwan. Time lag of knowledge stock was simulated to represent the actual relationship between R&D expenditures and cost reductions in power generation by knowledge stock. Analytical results demonstrate the GCE model is a useful tool to quantify the influences of cost reductions in power generation. The implications of analytical results are that institutional policy instruments play an important role in RE technologies achieving cost reductions and market adoption. The proposed GCE model can be applied to all high-technology cases, and particularly to RE technologies. The study concludes by outlining the limitations of the proposed GCE model and directions for further research.     

Opinion convergence in location: A spatial version of the Delphi method

This paper proposes a modified version of the Delphi method, starting from the assumption that in many situations the convergence of opinions can be considered in a spatial context. The Spatial Delphi we suggest is based, like the classical Delphi, on the judgments of experts, and it is useful in the consultations for decision and/or forecast purposes, provided that they concern matters of spatial location. The basis for the questionnaire is a map, on which each expert provides, as answer(s), one or more opinion-points, i.e., locations that, according to their opinion, are best for a specific purpose. We propose a method for narrowing the area of convergence along a multi-step procedure so that the final result of the consultation is a small portion of the initial territory with respect to the initial area considered. Besides a simulation study, we report also a prototype application with a panel of twelve experts.     

Does the Delphi process lead to increased accuracy in group-based judgmental forecasts or does it simply induce consensus amongst judgmental forecasters?

We investigate the relative impact of internal Delphi process factors - including panelists' degree of confidence, expertise, majority/minority positioning - and an external factor, richness of feedback - on opinion change and subsequent accuracy of judgmental forecasts. We found that panelists who had low confidence in their judgmental forecast and/or who were in a minority were more likely to change their opinion than those who were more confident and/or in a majority. The addition of rationales, or reasons, to the numeric feedback had little impact upon panelists' final forecasts, despite the quality of panelists' rationales being significantly positively correlated with accurate forecasts and thus of potential use to aid forecast improvement over Delphi rounds. Rather, the effect of rationales was similar to that of confidence: to pull panelists towards the majority opinion regardless of its correctness. We conclude that majority opinion is the strongest influence on panelists' opinion change in both the ‘standard’ Delphi, and Delphi-with-reasons. We make some suggestions for improved variants of the Delphi-with-reasons technique that should help reduce majority influence and thereby permit reasoned arguments to exert their proper pull on opinion change, resulting in forecast accuracy improvements over Delphi rounds.     

河北省制造业企业物流链信息技术投入产出效率评价

整合和管理物流供应链条不仅是降低企业运营和物流成本的关键,也是增强企业竞争力和促进企业升级的有效途径,而信息技术的投入又是决定物流链管理水平的重要因素.通过对河北省制造业企业物流链管理现状的调查,利用DEA分析方法对河北省制造业企业物流信息技术投入与企业效益进行投入产出评价,结果表明:河北省制造业企业物流链信息技术投入产出效率明显不高,尤其是中小企业投入产出效率更低,结果还显示大部分企业信息技术投入比例并不协调,物流信息技术(ERP、数据库)投入能力不足.     

The scope of “marketing” research in the nonprofit sector: Lessons from the last 20 years literature

Over the last several decades, the field of nonprofit marketing has produced a growing number of publications; however, little attention has been paid to examine what research topics have been studied by nonprofit scholars from the marketing perspectives. This knowledge production research contributes to the literature by reviewing trends in research themes and methodologies over the last 20 years among the articles for which authors use the terminology “marketing.” Employing a thematic review using text network analysis, and an in-depth methodology review, this study finds that nonprofit marketing studies have been shifting to become more subdivided and diversified in terms of research themes and methodologies. However, we also find that there is still room for further development, which we provided recommendations based on the findings. With its findings, this paper provides critical guidance for future studies.     

Gender Discrimination and Worker Selectivity: A Comparison of the Self-employed and Wage Earners

This study compares the size and nature of the gender earnings differentials for the self-employed and wage earners in Korea, taking into account the workers’ self-selection of each employment type. The two-stage estimates of the earnings equation, corrected for worker selectivity, are used to decompose the gender earnings differentials into productivity-related and discriminatory factors. Our results suggest that the size of the gender earnings gap is larger in the wage sector than in the self-employment sector, but not by large margin, and so is the discrimination effect when not controlled for worker selectivity. With worker selectivity controlled, the discrimination effect is greatly intensified in the wage sector, while it becomes not significant in the self-employment sector. These findings imply that the observed gender earnings gap in the wage sector is largely ascribed to discrimination against women, while the gender earnings gap in the self-employment sector is mostly due to productivity difference that, in part, is caused by worker selectivity.