Bayesian Model Selection for Beta Autoregressive Processes

We deal with Bayesian inference for Beta autoregressive processes. We restrict our attention to the class of conditionally linear processes. These processes are particularly suitable for forecasting purposes, but are difficult to estimate due to the constraints on the parameter space. We provide a full Bayesian approach to the estimation and include the parameter restrictions in the inference problem by a suitable specification of the prior distributions. Moreover in a Bayesian framework parameter estimation and model choice can be solved simultaneously. In particular we suggest a Markov-Chain Monte Carlo (MCMC) procedure based on a Metropolis-Hastings within Gibbs algorithm and solve the model selection problem following a reversible jump MCMC approach

A new competition model combining Lotka- Volterra model and the Bass model in pharmacological market competition

The diffusion of products that compete in the marketplace is a strategic issue for market analysts. In this paper, we propose a new competition model for two competing products essentially thought as an extension of a Lotka-Volterra competition model. This model was introduced the first time by Guseo (2004) but in that paper the application of the model in a real case was missing. This extension came from the observation that in a standard Bass model (1969) the role of innovators has a great importance because it incorporates the innovative effect due to external action (firms communication, advertising) that is proportional to residual market and consequently it is of great relevance in the initial part of diffusion process even if it progressively reduces. Lotka-Volterra models allow for a definition of the residual market of a product category which is more general with respect to alternative approaches. The residual market is not simply defined as the difference between the initial market potential and the sum of all brands adoptions. Conversely, competing products adoptions contribute to the residual market with different weights. This generates brand specific perceived residual markets. Furthermore, the model overtakes the heavy restriction of synchronicity between the two products giving a simple solution based on the Bass model

Diffusion of nuclear energy in some developing and graduated developing countries.

Electric power demand is increasing worldwide and, in the last years, energy policy has focused on expanding nuclear power, especially in developing countries. One of the key points surrounding this issue is the depletion time of uranium; further, forecasters had estimated that the use of nuclear reactors would come to a halt in 2020 by AIEA. It is apparent that we can no longer sustain the evolutionary model of energy consumption typical of the last century. The Fukushima disaster of 2011 reopened the debate about the use of nuclear energy to produce electricity. Japan, Switzerland and Germany decided to halt new nuclear projects. However, the question remains: would the world's uranium resources suce to meet nuclear energy projects, especially those slated in the developing countries? This paper oers an analysis of nuclear energy diffusion of some graduated developing countries (the Slovak Republic and South Korea) and some developing countries (Ukraine, China, Bulgaria, and India); moreover, it estimates the depletion time of uranium using a Generalized Bass model and OECD forecasts, with the uranium requirements scheduled for 2035. This study concludes that, given the estimated depletion time of uranium, and considering 50 years as a reasonable lifetime for reactors, the present international nuclear energy policy, and in particular the nuclear projects of the developing countries are not sustainable.

A comparison between American and European wind energy diffusion models.

The Kyoto Protocol of 1997 planned for all the subscribing countries a reduction of greenhouse gases by 5.2% with respect to the values of 1990. The production of electric energy through renewable energy systems is one of the ways to respect Kyoto limits. For this reasons, the countries that signed the protocol started to promote incentives policies for the adoption of these new technologies. The United States, although not subscribers of the protocol, is also committed in some way to create renewable electric energy. In particular with respect to the wind energy systems, the US is classified as one of the leader countries after Germany and Spain and often compared with European countries. On the contrary, since for comparing installed wind turbines capacity it is crucial to avoid all plain nuisance factors, we propose to compare the US diffusion model with that of Europe, that is a region similar for extension of geographical area and wind speed. Generalized Bass models were performed to estimate the life-cycle of innovations in the markets of the two regions

Short-term forecasts of the spread of wind power technology across countries

The production of electric energy through renewable energy systems is one way to respect Kyoto Protocol limits. The US, although not a subscriber to the protocol, is also committed in some way to creating renewable electric energy and, with respect to wind energy systems, is classified as one of the leading countries. Since when analyzing installed wind turbines capacity it is important to compare similar geographic areas, we propose here to compare the US with Europe. Some leading European countries are also included in the analysis. Estimates and short-term forecasts of the life-cycles of wind power innovations are provided through Generalized Bass models, detecting the effects of the local incentive policies. Furthermore, this class of models came first in the ranking of forecasting accuracy performances over a set of accuracy measures and forecasting horizons, when compared with the Standard Bass, Logistic, and Gompertz models