Abstract

The diffusion of innovations is an important process and its models have appli-cations in many fields, with particular relevance in technological forecast. The logistic equation is one of most important models in this context. Extensions of this approach as the Lotka-Volterra model have been developed to include the effect of mutual influences between technologies such as competition. However, many of the parameters entering this description are uncertain, difficult to estimate or simply unknown, particularly at early stages of the diffusion. Here, a systematic way to study the effect of uncertain or unknown parameters on the future diffusion of interacting innovations is proposed. The input required is a general qualitative understanding of the system: is the mutual influence positive or negative and does it apply symmetrically to either technology? Since the pa-rameters enter the problem via a set of coupled non-linear differential equa-tions, the approach proposed here goes beyond simple Monte-Carlo-like meth-ods where the result is an explicit function of the parameters. The methodology is developed in detail and applied the case of three types of upcoming electric vehicle propulsion technologies. The findings indicate that competition between electric vehicles and mild hybrid vehicles implies a slow decline of the latter. The approach can easily be generalised to include other initial conditions, more technologies or other technological areas to find stable results for future market evolution independent of specific parameters.

Abstract

Replacing conventional vehicles by electric vehicles (EVs) and increasing the use of carsharing are two strategies to reduce the environmental impact of car driving. However such a societal transition towards the use of more sustainable modes of transport will strongly depend on citizens' willingness to support this process. For this reason, this paper tries to identify factors which are related to the individual likelihood to change to more sustainable modes of transport. It draws on an adapted version of Rogers' diffusion of innovation model (DOI) and earlier work by the authors. It presents new findings from an online survey (n=1548) in one of Germany's show case regions for electric vehicles. Findings point out that relatively small shares of respondents already use these sustainable modes of transport (.6% for EV ownership and 5.3% for carsharing). Similarly, the shares of individuals who are very likely to use them in the near future (4.2% and 4.6% respectively) are also small. Much more individuals are interested in EVs (55.9%) than in carsharing (21.2%), and large groups are not interested (37.7% for EVs, 68.9% for carsharing). There are several significant sociodemographic differences between the respective four adoption groups. Furthermore, consistently, evluations are significantly more positive the higher the likeliness of adoption across groups. Based on regression models, it turns out that perceived compatibility with daily life is the most important factor influencing the attitudes towards EVs or carsharing across all groups.

Abstract

This paper explores how conceptions of luxury and status affect the manner in which a relatively novel technology—an electric vehicle— diffuses across societies. To do so, it combines Veblen’s notion of conspicuous consumption and Roger’s diffusion of innovation by proposing a new theoretical variation, which we term “conspicuous diffusion.” The paper sketches natural connections between the two theories, namely how conspicuous consumption relates to technological and societal development, and how diffusion of innovation is intrinsically connected to status. In combining these approaches, we hypothesize that the success of an innovation is guided by its adherence to the canons of conspicuousness and conspicuous value, which it loses as the innovation diffuses across the population. To illustrate the explanatory power of conspicuous diffusion, we examine the status of electric vehicles in the Nordic region, based on original data from multiple methods, including expert interviews and focus groups. We find that conspicuous diffusion can explain previous failures and current successes of electric vehicle diffusion patterns. The paper concludes with recommendations for policymakers, industry, and academia.