Search

In this paper we investigate a dynamic setting of environmental taxation, for which the government imposes a tax rate in order to internalize externalities caused by polluting firms. The basic model consists of the intertemporal maximization problem for an additively separable utility which is subject to the pollution accumulation constraint. We analyze some various aspects of the same setting such as the leader-follower, the social planning and the simultaneous move game. The model is very simple and has some similarities with capital taxation models. The crucial variables of the model are the tax rate as a control and the pollution stock as a state. We discuss a scheme in which polluters adopt Markovian emission strategies with respect to the flows, and the tax rate imposed is, in the most cases, a constant depending on the discount rate. Moreover, computing the time paths for the control and state variables, the welfare index analysis, that follows, reveals substantial inefficiencies caused by the leader-follower setting, compared with the social planning optimal control setting. [ABSTRACT FROM AUTHOR]

In this paper we examine the innovative performance of Greek firms in terms of female participation in research and technological development. We rely on the final results of a research project on women in innovation, technology and science, based on 372 questionnaires selected on a two-year time period (2004-2006). For this reason a number of variables are used, like the total number of women employees by age, education level, firm size and sector, as well as women in product and in process innovations. Other variables like their position in the firm (owner, manager), equality in job enrichment, salary, education-training and promotion are also considered. The collected variables are used in a generalized linear model formulation to evaluate the relative risk associated with them. [ABSTRACT FROM AUTHOR]

Traditional economic theory, up to the middle of the twentieth century, builds up the production functions regardless the inputs' scarcity. In the last few decades has been clear that both the inputs are depletable quantities and a lot of constraints are imposed in their usage in order to ensure economic sustainability. Furthermore, the management of exploitation and use of natural resources (either exhaustible or renewable) has been discussed by analysing dynamic models applying methods of Optimal Control Theory. This theory provides solutions that are concerned with a single decision maker who can control the model dynamics facing a certain performance index to be optimized. In fact, market structures or exploitation patterns are often oligopolistic, i.e. there are several decision makers whose policies influence each other. So, game theoretical approaches are introduced into the discussion. According to the theory of continuous time models of Optimal Control, the appropriate analogue of differential games is used. Roughly, this is the extension of Optimal Control, when there is exactly one decision maker, to the case of N (N≥2)decision makers interacting with each other. [ABSTRACT FROM AUTHOR]

Dynamic modeling is general and recently the most interesting perspective to solve a dynamic economic problem based on Pontryagin's maximum principle. Moreover traditional economic theory, up to the middle of twentieth century, builds up the production functions regardless the inputs' scarcity. Nowadays it is clear that both the inputs are depletable quantities and a lot of constraints are imposed in their usage in order to ensure economic sustainability. For example the input "oil" used in the production is a non renewable resource so it can be exhausted. In a same way every biomass resides in ecosystems is a resource that can be used in a generalized production function for capital accumulation purposes but the latter resource is a renewable one. The purpose of this paper is the presentation of some natural resources dynamic models in order to extract the optimal trajectories of the state and control variables for the optimal control economic problem. We show how methods of infinite horizon optimal control theory developed for natural resources models. [ABSTRACT FROM AUTHOR]

Summarizes the available information on the costs of the main technologies for nitrogen oxide abatement. How are nitrogen oxides formed; Abatement options for nitrogen oxide emissions reduction; Assumptions used in derivation of abatement cost curves.

Energy is considered as a commodity nowadays and continuous access along with price stability is of vital importance for every economic agent worldwide. The aim of the current review paper is to present in detail the two dominant hedging strategies relative to energy portfolios, the Minimum-Variance hedge ratio and the expected utility maximization methodology. The Minimum-Variance hedge ratio approach is by far the most popular in literature as it is less time consuming and computationally demanding; nevertheless by applying the appropriate multivariate model Garch family volatility model, it can provide a very reliable estimation of the optimal hedge ratio. However, this becomes possible at the cost of a rather restrictive assumption for infinite hedger's risk aversion. Within an uncertain worldwide economic climate and a highly volatile energy market, energy producers, retailers and consumers had to become more adaptive and develop the necessary energy risk management and optimal hedging strategies. The estimation gap of an optimal hedge ratio that would be subject to the investor's risk preferences through time is filled by the relatively more complex and sophisticated expected utility maximization methodology. Nevertheless, if hedgers share infinite risk aversion or if alternatively the expected futures price is approximately zero the two methodologies become equivalent. The current review shows that when evidence from the energy market during periods of extremely volatile economic climate is considered, both hypotheses can be violated, hence it becomes reasonable that especially for extended hedging horizons it would be wise for potential hedgers to take into consideration both methodologies in order to build a successful and profitable hedging strategy. [ABSTRACT FROM AUTHOR]