An obstacle to the widespread adoption of environmentally friendly energy technologies such as stationary and mobile fuel cells is their high upfront costs. While much lower prices seem to be attainable in the future due to learning curve cost reductions that increase rapidly with the scale of diffusion of the technology, there is a chicken and egg problem, even when some consumers may be willing to pay more for green technologies. Drawing on recent percolation models of diffusion by Solomon et al. [7], Frenken et al. [8] and Höhnisch et al.[9], we develop a network model of new technology diffusion that combines contagion among consumers with heterogeneity of agent characteristics. Agents adopt when the price falls below their random reservation price drawn from a lognormal distribution, but only when one of their neighbors has already adopted. Combining with a learning curve for the price as a function of the cumulative number of adopters, this may lead to delayed adoption for a certain range of initial conditions. Using agent-based simulations we explore when a limited subsidy policy can trigger diffusion that would otherwise not happen. The introduction of a subsidy policy seems to be highly effective for a given high initial price level only for learning economies in a certain range. Outside this range, the diffusion of a new technology either never takes off despite the subsidies, or the subsidies are unnecessary. Perhaps not coincidentally, this range seems to correspond to the values observed for many successful innovations.JEL Codes: C61, H23, O32, O33

Agent-based models have improved the standards for empirical support and validation criteria in social, biological, cognitive and human sciences. Yet, the inclusion, in these models, of vertical interactions between various aggregation levels remains a challenge. We study analytically, numerically and by simulation the generic consequences of interactions between the collective and its individual components:  the appearance of an autocatalytic loop between the dynamics of the collective and its components;  the system, which is dominated by a limited number of factors amplified by this collective↔individuals autocatalytic loop;  the microscopic features, which are not involved in the autocatalytic loop and are irrelevant at the systemic level; and  how the above clarify the interplay between macroscopic predictable features and the ones dependent on random unpredictable individual events. Using the social and market percolation framework, we study the dramatic effects of the collective↔individuals autocatalytic loop on economic crisis propagation:   the percolation transition becomes discontinuous;  there are a few relevant regions and regimes corresponding to a quite diverse range of response policy options;  there are stability ranges where appropriate policies can help to avoid macroscopic crisis percolation; and   beyond those regions the systemic crisis might become unstoppable.

The introduction of environmentally friendly innovations in both transport and energy sectors are included in the list of priorities of the European Union political agenda. This paper investigates the environmental consequences of the introduction of hydrogen and fuel cells technology in the European economic system by applying environmental input -output analysis and life cycle assessment tools. Hydrogen is produced through the reforming of natural gas and it is employed in fuel cells buses that offer transport services to final consumers. We have built three scenarios based on different assumptions on the final demand. We have shown the results for three impact categories: global warming, photochemical oxidation and acidification. The results suggest that the use of hydrogen in fuel cells buses is only environmentally desirable if accompanied either by the employment of renewable sources or by carbon dioxide capture, or both.KEY WORDS: Environmental input -output analysis, life cycle assessment, hydrogen and fuel cells technology

Dumping actions and anti-dumping policies were regularly on the political agenda for several years in the pre-World War I period in Europe and the United States. In Italy, politics, economic circles, and scholars were engaged in debate on whether to protect sensitive industries threatened by sales below cost in their home markets, practiced by foreign competitors. Einaudi and his school of economics tackled the issue with several publications. In this paper we focus on Jannaccone’s essays, which he contributed to both a symposium in Riforma sociale in March 1914 and an issue in Rivista delle società commerciali in June 1914. Although we recognize that Viner (1923) theoretically systematized dumping in the wider framework of international trade, we nevertheless claim that the theoretical origin of dumping, in a context of imperfect competition, was Jannaccone’s essay. We show that Jannaccone proposed an early theory of dumping as an instance of the more general theory of price discrimination. He defined and classified dumping; he developed a static analysis of its profitability; he investigated the effects of dumping in both domestic and foreign markets; and he analyzed the effect of protectionism and its policy implications.