Cross-country diffusion of photovoltaic systems: Modelling choices and forecasts for national adoption patterns

In this paper we propose an innovation diffusion framework based on well-known Bass models to analyze and forecast national adoption patterns of photovoltaic installed capacity. This allows for interesting comparisons among several countries and in many cases highlights the positive effect of incentive policies in stimulating the diffusion of such a technology. In this sense, the Generalized Bass Model proves to be essential for modelling and forecasting. On this basis, we observe important differences in the investments made by countries in the PV sector and we are able to identify whether and when these investments obtained the expected results. In particular, from our analysis it turns out that in some cases incentive measures have been certainly effective in facilitating adoption, while in some others these have not been able to produce real feed-back. Moreover, our cross-country approach is able to forecast different stages in PV evolution: whereas some countries have already entered the mature stage of diffusion, others have just begun. This result may suggest various considerations about the competitive advantage of those countries that invested in alternative energy provisions. In spite of a very diversified scenario in terms of historical patterns of diffusion, we may report, as a general result, the fragile role of innovators for this special market and the dominance of imitative behaviour in adoptions.     

考虑负面口碑的竞争性创新扩散研究：概念框架与仿真分析

创新往往以市场扩散失败而告终，但当前研究常常围绕成功的创新扩散展开。创新扩散存在多层意义，而不仅仅体现在扩散数量上。在Bass扩散模型的基础上，构造考虑竞争与负面口碑影响的多状态创新扩散模型，利用系统动力学方法探讨不同情境下的创新扩散。仿真结果显示，竞争与负面口碑将从数量和价值角度影响创新扩散过程与结果；同时，作为一种复杂系统，影响因素在类别与品牌层面上的效果并不一致。     

Modelling the faddish, fashionable and efficient diffusion of agricultural technologies: A case study of the diffusion of wool testing technology in Australia

This study investigates the nature of innovation diffusion in an agricultural context. The dominant agricultural diffusion models assume that an economically rational choice is made to adopt or reject agricultural technologies. However, recent studies of agricultural innovation highlight the ‘irrational’ and potentially ‘inefficient’ nature of the diffusion in this context. To investigate how and why agricultural technologies are adopted or rejected, we examine the diffusion of wool testing technologies in the Australian wool industry using the Bass diffusion model and Abrahamson's diffusion and rejection typology. The results show that diffusion of agricultural innovation is not simply an efficient choice made to close observable performance gaps. The findings suggest that the adoption of inefficient innovations and the rejection of efficient innovations can be driven by an adopter's social context, powerful external influences and imitation within an adopter group and that these drivers change over time, suggesting an evolutionary social process underlies the diffusion of agricultural technologies.     

管理领域中若干扩散性问题的元胞自动机模型

元胞自动机通过模拟个体之间的相互作用得到宏观结果,作为一种微观模型已经越来越广泛地应用于管理领域的研究。介绍了元胞自动机模型的机理,并分别针对管理领域中文化舆论传播、传染病传播以及创新扩散建立了元胞自动机模型进行研究。     

Market potential dynamics in innovation diffusion: Modelling the synergy between two driving forces

The presence of a slowdown in new product life cycles has recently received notable attention from many innovation diffusion scholars, who have tried to explain and model it on a dual-market hypothesis (early market-main market). In this paper we propose an alternative explanation for the slowdown pattern, a dual-effect hypothesis, based on a recent co-evolutionary model, where diffusion results from the synergy between two driving forces: communication and adoption. An analysis of the synergistic interaction between communication and adoption, based on the likelihood ratio order or on a weak stochastic order, can inform us of which of the two had a driving role in early diffusion. We test the model on the sales data of two pharmaceutical drugs presenting a slowdown in their life cycle and observe that this is identified almost perfectly by the model in both cases. Contrary to the general expectation, according to which communication should precede adoption, our findings show that adoptions may be the main driver in early life cycle; this may be related to the drug's specific nature.     

Investigation of the effect of secondary market on the diffusion of innovation

In the high-tech product market, the number of hungry adopters, a new type of early adopters who buy new products and sell them soon in the on- or off-line secondary market to seek for the other new products, has been increasing due to the short product life cycle of high-tech products and the low transaction cost on the Internet. This new phenomenon means that it is inappropriate to consider customers only in the primary market as total adopters in innovation diffusion modeling, since purchasers in the secondary market also have a word-of-mouth effect on the remaining non-adopters. To explain this new phenomenon, we modify the basic Bass diffusion model by incorporating the effect of the secondary market and conduct an empirical analysis. As a result, we conclude that the basic Bass model is likely to overestimate sales volume and tends to forecast lagged peak time when there is an effect from the secondary market. This means that applying a diffusion model to high-tech products without considering the secondary market effect would provide an inaccurate market forecast.     

A choice-based multi-product diffusion model incorporating replacement demand

This study proposes an integrated forecasting model that incorporates both first purchase diffusion and replacement component of sales in predicting multi-product diffusion patterns. The model consists of a two-stage procedure that customers undertake during purchase occasions according to a diffusion process or replacement process, and at each occasion, they make purchase incidence decisions and product choices according to a choice model. By incorporating various exogenous factors in the choice model, the model can identify the impact of each factor on customers' purchase incidence decisions and choice decisions among various product sub-categories. This approach enables us to understand the overall process of customers' purchasing behavior and to separate total sales amount into sales to three consumer segments: first-time buyers, customers who repurchase the same product category and customers who change their previous product category. We applied the proposed model in the forecasting multi-product framework; forecasting sub-category level automobile sales and brand level mobile terminal sales in the South Korean market. The results of the empirical studies showed that incorporating the replacement components into the multi-product diffusion framework is useful not only in understanding the demand interaction among automobile categories and among mobile handset brands, but also in producing more accurate long-term sales forecasts compared to previous multi-product diffusion models.     

Contagion effects of electronic commerce diffusion: Perspective from network analysis of industrial structure

This study presents a quantitative method for investigating the diffusion of e-commerce adoption using social network analysis methodologies. The contagion effects on innovation diffusion are examined by two different social network models: the cohesion model, which is based on diffusion by direct communication, and the structural equivalence model, which is based on diffusion by similarity of network position. This study then empirically examines a sample of e-commerce diffusion taken from the Taiwan's industrial structure in 2001. The analytical results show that e-commerce diffusion among firms in Taiwan exhibits both contagion effects, but that the mimetic behavior is predicted better by network position than by interactions with others.     

基于Bass模型的品牌扩散模型研究综述

总结回顾了基于Bass模型的品牌扩散模型的主要研究进展,依据是否考虑了重复购买因素将品牌扩散模型分为品牌首次购买模型和品牌尝试-重复购买模型,并对两类模型进行了归纳和比较;探讨了在放宽基本扩散模型限制性假设方面的主要成果,并指出了未来研究的方向。     

考虑影响不对称性的创新扩散与网络结构协同演化建模：基于信息熵与累积优势的仿真研究

创新扩散发生于社会系统中并通常与社会系统存在交互作用。网络是体现社会系统的重要手段，但已有研究中的扩散网络多为无向网络且具有静态或外生动态性质，上述处理方式忽视或无法体现扩散与以网络形式出现的社会系统的协同演化以及个体间的不对称影响。基于有向网络，提出能够体现创新扩散与网络协同演化的描述性框架，从信息搜寻与降低认知失调视角出发，基于信息熵与累积优势机制，在个体层面构造网络演化与创新采纳数学模型。在RepastSimphony2.7开发平台下，利用基于Java的智能体建模方法展开系统仿真实验。基于实验数据的描述性结果揭示，动态网络与静态网络下的创新扩散存在显著不同，网络结构演化将强化节点出度的不均衡状况，更优的扩散结果往往与更不均衡的节点出度分布同时出现，其它因素包括大众传播与人际传播等也会影响扩散与网络的协同演化；交互作用存在于控制变量间。推断性结果确认了控制变量影响与交互作用的普遍存在。     

Introduction of microcomputers at an academic institute— Study of an innovative process

In the following study the process of microcomputer adoption and diffusion at an academic institute is described and the implications of this innovation for faculty and students are assessed. The individual acquisition data are analyzed using the Mansfield diffusion model. In addition, I report a case study describing the centralized purchase decision-making process at the institute, and conclude with a longitudinal empirical study that examines the development of microcomputer uses and users' attitudes over a period of 1 year. The results show mainly that the adoption process is quite slow, although the response of the users is generally found to be quite favorable.     

Predicting early adoption of successive video player generations

Early adopters play an important role in the innovation diffusion process. Over the past decades, many factors have been identified as predictors for early adoption of innovations. Less attention has been paid to the relationship between the early adoption of one generation of a specific product and the early adoption of successive product generations. This paper analyzes how early adoption of a new product generation depends on ownership, purchase experience and adoption times for previous generations of the same product. The paper develops predictive models of early adoption for four generations of video player products, based on a survey among 815 Australian consumers. The model allows the testing of various hypotheses. It is shown that previous generation variables outperform conventional socio-demographic and psychographic variables in predicting early adoption but also that the two variable types complement each other. The best predicting models include both previous generation and socio/psychographic variables. It is concluded that previous generation models have substantial merits for new product forecasting as they are more parsimonious than conventional models and the data required to estimate them is relatively easy to obtain.     

The impact of competition,and economic globalization on the multinational diffusion of 3G mobile phones

To discover differences in technology diffusion of 3G mobile phones across countries, we investigate the impact of market factors, measured by competitive fractionalization, and economic globalization across countries using a multi-country diffusion model. We incorporate comprehensive socioeconomic and telecommunications data covering 35 geographically and economically diverse countries and control for covariates from literature. We used the Non-linear Mixed Modeling (NLMIXED) approach in SAS with pooled multi-country data to estimate a generalized Bass model taking into account unobserved heterogeneity in market saturation levels, a major source of inter-country differences. Our substantive findings are: the significance of the impact of competitive fractionalization on the likelihood of adoption and on the market potential; the significance of the impact of economic globalization on market growth. Our findings will aid international managers and regulators in their strategy and policy formulations. Finally, we demonstrate model validity by model fit and predictive accuracy.     

产业融合与融合产品的需求增长--基于修正的Bass模型的分析

产业融合形成的创新性产品所带来的需求增长包含了两个过程:一是对产业融合的原有产业市场需求的替代,二是创造出原有市场之外的新的市场需求。本文在对Bass及相关模型的假设条件作出适当修正的基础上,建立了能够方便、准确地对融合产品的需求增长状况进行分析和估计的产业融合需求增长模型。基于这一模型,本文对融合产品的需求替代和创新、融合产品的需求增长估计以及融合产品的需求增长趋势进行了经验验证和预测。     

Identification of effective opinion leaders in the diffusion of technological innovation: A social network approach

Opinion leaders are the people in a social network who have the greatest influence on other people's acknowledgment or adoption of products/services in the diffusion process of technological innovation. In this research, we investigate which opinion leader is the best marketing choice in terms of diffusion speed and maximum cumulative number of adopters, using a social network approach and threshold model. On the basis of the simulation result, we find that opinion leaders with high sociality are the best ones for fast diffusion, whereas those with high distance centrality are the best ones for the maximum cumulative number of adopters. Moreover, we conclude that the characteristics of effective opinion leaders selected as initial adopters could vary depending on the characteristics of the social network and type of innovation. Finally, we find that opinion leaders affect the diffusion process only when the percentage of initial adopters reaches a critical mass.     

基于技术创新扩散环境的Bass扩散模型修正研究

对技术创新扩散环境进行了界定和分类,并就环境因素对技术创新扩散的影响进行了分析,得出由于环境的不确定性决定了技术创新扩散轨迹的不稳定性的结论。在此基础上,从环境因素的影响入手,分别对基本的Bass模型和扩展的Bass模型进行了修正,并对新模型的性质进行了分析。     

小世界网络下用户创新扩散效果分析

本文对用户创新的概念及相关研究成果进行了阐述,分析了用户创新扩散的特性;运用WS小世界网络模型构建了用户创新扩散的网络模型,并对扩散效果进行了模拟分析。结果表明:用户创新扩散在不同的网络结构下呈现出不同的结果;创新采纳比例在小世界区间达到最大;随着网络随机化程度的加大,平均创新知识水平变得更高,知识的均匀扩散能够更快实现。最后进行了案例分析。     

A dynamic diffusion model for managing customer's expectation and satisfaction

The paper aims at answering the generic question on how suppliers make the suitable and well-timed decisions in diffusing new technology effectively to adopters. Three major attempts are made for the study: First, investigating the entire process of the adoption and diffusion of technology innovation with reasonably well-accepted models in each areas. Second, proposing an integrated model by concatenating in structured manner the three prominent models for the management of technology innovation such as diffusion model, adoption model, and customer satisfaction model. Third, exploring the dynamic mechanism underlying outward behaviors of the integrated model proposed in the study which depicts the causal relationships that influence technology adoption and diffusion behaviors. An exploration of the dynamic mechanism underlying outward behaviors of the integrated model is presented in the study by introducing the system dynamics simulation technique. These attempts made for the study and the results perhaps allow both researchers and practitioners to gain insight into the causal factors influencing customers' adoption decision making processes and thereby into the potential diffusion patterns resulting from those adoption processes.     

Contagion effects of national innovative capacity: Comparing structural equivalence and cohesion models

The effective promotion of national innovation performance is a crucial component of national innovation policy. This study examines network contagion effects of national innovative capacity via the international diffusion of embodied and disembodied technology by two different social network models: the cohesion model, based on diffusion by direct communication, and the structural equivalence model, based on diffusion by network position similarity. This investigation then utilizes data of 42 countries during 1997 to 2002 to empirically examine their network relationship. The analytical results demonstrate that international technology diffusion influences national innovation performance through contagion effects, but that the international similarity of national innovative capacity performance is more accurately predicted by network position than by interactions with others; and this study result provides a new perspective for science and technology policy makers.     

Performance comparison of two diffusion models in a saturated mobile phone market

This research examines a performance comparison of the Lotka–Volterra (LV) and extended Bass models in the saturated mobile phone market of the Republic of Korea. A three species LV model is developed and applied to Korean mobile phone service providers in terms of competitive impact. Fitting the historical data of the Korean mobile communication service market, the results show that the goodness of fit of the three species LV model in the case of competition among three companies is better than that of the extended Bass model. The advantages and disadvantages of the two models are discussed based on the results of empirical tests.