درخت حوزه‌های تخصصی

Chief executive officers (CEO), as the central pillar directing companies at the capital market level, plays a critical role in making investment decisions to de-crease agency costs and maximize shareholders’ wealth; however, their psycho-logical attitudes and perceptions lead to different investment functions of these companies in a competitive market. Accordingly, this study aimed to detect the propositional arrays of the investment functions using Q analysis in order to identify the CEOs’ mental typology in distinguishing investment functions. The present study was carried out with the participation of 13 CEOs from Tehran Stock Exchange companies during a one-year period (2018-2019). The study encompassed two different phases. In the first phase, content analysis was used to identify the phrase Q of the CEOs’ investment functions. In the second phase, Q analysis was adopted to typify the CEOs’ investment functions, which was based on the subjective cognition of the target population and contributed to the development of the approaches in line with the research objectives. The results confirmed the existence of three mental patterns in the CEOs regarding the in-vestment functions in the capital market. These mental patterns were ‘investment function in stock market indices’ as the first mental pattern, ‘investment function in risk control’ as the second mental pattern, ‘strategic investment function’ as the third mental pat-tern. The study results revealed different types of investment functions among the CEOs’ of stock exchange companies and thus contributed to the development of financial theories from the perspective of CEOs’ cognition.

This study examines the criterion of value at risk from another perspective and presents a new type of mean-value at Risk model. To solve the portfolio optimization problem in Tehran Stock Exchange, we use NSGA II, MOACO, and MOABC algorithms and then compare the mean-pVaR model with the mean-SV model. Given that, finding the best answer is very important in meta-heuristic methods, we use the concept of dominance in the discussion of multi-objective optimization to find the best answers and show that, at low iterations, the performance of the NSGA II algorithm is better than the MOABC and MOACO algorithms in solving the portfolio optimization problem. As the iteration increases, the performance of the algorithms improves, but the rate of improvement is not the same, in a way, the performance of the MOABC algorithm is better than that of the NSGA II and MOACO algorithms. Then, to compare the performance of the “mean-percentage of Value at Risk” model and the “mean-semi variance” model, we examine both models in the standard mean-variance model and show that the mean-pVaR model, compared to the mean-SV model, Has better performance in stock portfolio optimization.

Pension funds are major concerns and future threats to the economy of de-veloping countries. In general, pension funds are among the most sensitive and complicated modern financial institutions in today’s world, as well as an important component of the national economy to achieve the goals of the social security system. The present study was only focused on the dimensions and prioritization of the influential factors in evaluating the impact of pension funds. This could be an important step toward accurate policymaking in this regard within a shorter period and with decreased costs by recognizing the important factors. This was an applied research in terms of the objectives and involved a mixed method in terms of the design. Data were collected in two consecutive stages using the descriptive survey method. The first stage involved a qualitative assessment using the content analysis method, and the second stage was carried out using a decision-making mathematical model known as the fuzzy DEMATEL method. The two stages facilitated the identification of the influ-ence and interaction of the factors and prioritized the identified indexes. The fuzzy DEMATEL technique is a simple and efficient model applied to rec-ognize and rank the most important factors. The factors were calculated based on the opinions of experts using the fuzzy DEMATEL method. Ac-cording to the results, the three most important factors in this regard were upstream rules and regulations, inflation, and investment strategies.