Why the determinacy condition is a weak criterion in rational expectations models

This paper disputes what Blanchard and Kahn have reported as the solution of linear rational expectation(RE) systems many years ago. Their method leads to traditional determinacy condition which is used very much nowadays. In this paper we have a new look to the mathematical procedure of this solution method and the main problem in their solution will be shown. We introduce a new methodology for modeling the systems with expectation, while in future this way of modeling can be used to replace traditional RE models.Rational expectation; Determinacy condition; Stability; Uniqueness; Predictive control

Why the determinacy condition is a weak criterion in rational expectations models

This paper disputes what Blanchard and Kahn have reported as the solution of linear rational expectation(RE) systems many years ago. Their method leads to traditional determinacy condition which is used very much nowadays. In this paper we have a new look to the mathematical procedure of this solution method and the main problem in their solution will be shown. We introduce a new methodology for modeling the systems with expectation, while in future this way of modeling can be used to replace traditional RE models

A decision support system for evaluating effects of feed-in tariff mechanism: dynamic modeling of Malaysia’s electricity generation mix

Malaysia has abundant potentials of renewable energy resources mainly because of its rich agriculture that makes high potential in bio-power and its tropical climate, which provides sufficient sunlight for utilization of solar systems. Feed in Tariff mechanism has been applied since 2011 in Malaysia to expand utilization of renewable energy for electricity generation. In this study, a broad range of data is gathered to develop a comprehensive system dynamics model to evaluate the impacts of Feed in Tariff mechanism on the generation mix of Malaysia during a 20-year period between 2011 and 2030. Results demonstrate that although the policy may lead to a satisfactory level of target achievement but the Malaysian government may face an increasing shortage in its RE fund budget starting around 2019 unless it increases its income sources by rising the surcharges on electricity bills or decreases its expenditures by optimizing the amount of FiT payments in different periods. The sensitivity analysis illustrates that the more funding will not lead to a more sustainable generation mix unless it is paid in the right time and in the right direction. Using this model, policymakers can carry out analysis to determine the amount of money that must be collected from the electricity consumers through the surcharges on electricity bills as well as the amount of feed in tariff to be paid for different renewable resources in different periods

A predictive multi-agent approach to model systems with linear rational expectations

Expectation formation plays a principal role in economic systems. We examine and revise the standard rational expectations (RE) model, generally taken as the best paradigm for expectations modelling, and suggest a new method to model rational expectations. Conventional conditions that assert the stability and uniqueness of popular solution methods are shown to be insufficient. The agent-based new modelling approach suggested in this paper will be shown to lead to uniquely stable solutions

A predictive multi-agent approach to model systems with linear rational expectations

Expectation formation plays a principal role in economic systems. We examine and revise the standard rational expectations (RE) model, generally taken as the best paradigm for expectations modelling, and suggest a new method to model rational expectations. Conventional conditions that assert the stability and uniqueness of popular solution methods are shown to be insufficient. The agent-based new modelling approach suggested in this paper will be shown to lead to uniquely stable solutions

Why do Students use Virtual Social Networks in Iran: a System Approach

Rise of Social Network Sites, such as Facebook, significantly influences the behaviour of students around the world nowadays. Different studies have been done up till now to investigate different stimuli on using Facebook. In this study, as one of the first attempts to investigate dynamic influencing factors, systems approach is used to consider such factors’ effects and their feedback simultaneously. After finding major factors and estimating the behaviours, in order to verify effects of them, an online questionnaire was prepared to gather Iranian Facebook users’ attitudes toward these factors. After interpreting answers, we ran a dynamic simulation model and made some discussions about the effects of different factors on the time which users spend in Facebook. The results show that negative impact of filtering causes decrease on time users spend in Facebook. Under current situation, although filtering on internet has its effects on users in Iran, tendency toward using different facilities of Facebook is strong enough to overcome these negative effects