فهرست مطالب جعفر عبادی

The expected value of a company’s stock can change in response  to new inside and outside information, depending on the nature of the company. The main purpose of this paper is to test the effect of new and different types of information on the bid-ask spread. Accordingly, using with an event study on  a selected sample, we identify release days and specify dummy variables and then we analyze the effect of information on the bid-ask spread with a panel data odel.Other variables include stock return, transaction volume, market return, and the percentage  change in the dollar’s price, oil price, and the average price of precious Metals. Results of the empirical model show that while the new inside information has a positive effect on the liquidity, changes in the outside information lead to a wider bid-ask spread and  lower  stock liquidity. Therefore, outside policy has a negative effect through informational risk and the stability of the outside variable is important for the market’s performance.

It is a fact that “1 Person 1 Vote” is the most common voting system in democracies worldwide. But, when we ask “How about its efficiency in preference revelation?” the answer is “There are lots of other voting systems with more efficiency”. Two of the most recent studies in this field are “Liquid Democracy” and “Quadratic Voting (QV) Mechanism”. By using “Liquid Democracy” voters can delegate their votes to other voters, and by using “Quadratic Voting Mechanism” voters can buy more votes via spending money. This paper’s contribution is combining the two recent studies and designing “Adjusted Quadratic Voting Mechanism”. In fact, this contribution makes it possible to formulize Liquid Democracy and votes’ delegation in the context of Quadratic Voting (QV) Mechanism.

This paper extends an information-based model for an order market with asymmetric information. The new assumption in this expanded model is that possibility of asymmetric influence of changes in inside and outside information. However, other models generally assume that changes in these two types of information have the same value, or focus only on changes in internal information. Therefore, in the new extended model, uninformed traders face informed internal and external traders. In the new equilibrium, when the effect of external information is larger than that of internal information for the stock, in the optimal case uninformed traders choose a lower bid price and a higher ask price as the equality effect of these two types of information, and in the opposite case they choose a higher bid price and a lower ask price.

One of the most challenging issues related to the monetary policy is the causes and origins of inflationary shocks and biases. There are two approaches to the monetary policy in general: first, monetary policy based on discretion, and second, monetary policy based on a specific rule. Economists of New Classical School believe that monetary policy should be based on a monetary rule. Accordingly, the cause of inflationary shocks and biases can be considered as a violation of the monetary rule. They believe that economic agents make their expectations rationally. Therefore, an announced monetary policy will not have a real impact and will only cause inflation. As a result, an economists' effort could be to explain the government's motives for violating the monetary rule and to make policy recommendations based on it. This article tries to provide a new solution to the problem of violation of the monetary rule by using a special type of mechanism so called "Clark mechanism" (pivotal or person-centered mechanism) as well as designing micro-bases for the government behavior and rational agents and relying on the issue of government reputation.

The main purpose of this article is to study the transmission of systemic risk from a particular mutual fund to the rest of the mutual funds in Iran Capital Market. Applying the multivariate GARCH model with the Dynamic and constant Conditional Correlation method, we examine the correlation structure of daily net return of the mutual fund portfolios during the period from March 21st, 2011 to March 21nd, 2020. We find the hypothesis of the existence of systemic risk in Iran Capital Market cannot be rejected and the results indicate that the mutual funds are subject to the systemic risk. According to the estimation results of the model, in which Delta δ is significantly positive), it is expected that the conditional correlation among mutual funds to increases following the initial shock in their return series. Also, since the significant Gama coefficient is less than one but very close to it , we could expect long-lasting shocks and persistent uncertainties. The study suggests some managerial solutions for developing a prudential regulation policy to prevent and control systemic risk and to mitigate its effect. Such solution necessitates the establishment of institutions crucial for capital market development, including rating agencies, asset management companies, investment adviser Institutes, and regulation and regulatory agencies as well.

In recent years, higher education in Iran has faced a variety of problems, such as university extra seats, unemployment of graduates, and so on, which cause critical challenges to educational planners and policy makers. Examining main determinants of the applicants’ choice is an important remedy to thses challenges that can be done through developing an appropriate university-discipline choice model. Results derived from such a model, can help educational planners to rectify the challenges and also improve the quality of the applicants’ choices. In other words, understanding the university choice models of applicants helps to understand university choice behavior in Iran and to improve the quality of their university choice, higher education policies, and the decisions of university administrators. In this article, the model of university choice and its determinants in terms of gender, occupation, and residence are designed and estimated using data on the characteristics of a randomly selected sample of participants in the 1397 entrance exam of Electrical Engineering master degrees. The data included information on the field chosen by participants who were allowed to choose the study field and select at least one university-location course. The results of the analyses emplying Rank-ordered logistic model, show a high tendency of the applicants to attend the state universities located in Tehran city and the capitals of Iran’s provinces. Women tend to prefer Tehran more than men and unemployed tend to be significantly more exposed to the daily courses of Tehran city universities.

In order to analyze the labor market through search and matching theory, we need deep parameters namely, rate of inflow to the unemployment pool and job-finding rate. In other words, these rates are primary parameters of matching function; hence, estimating these parameters is an essential step for the use of search and matching theory in every economy. In this paper, we estimate these rates of Iran’s economy using Simulated Method of Moments (SMM) as a baseline for future studies in this framework. We use the unemployment rate and the number of unemployed workers which were unemployed less than one month. We find estimates of around 0.1 and 0.32 for rate of inflow to unemployment and job-finding rate, respectively, which are lower than the amounts estimated for the United States and other developed countries. This is a sign of some labor market irregularities in Iran economy. For example, it shows that the probability of experiencing long-term unemployment/employment by unemployed/employed ones is high because of lower job-finding and inflow to unemployment rates.

Financial stability is amongst the issues that have been increasingly considered over the past two decades. Today, money and capital markets play a substantial role in the development of societies, but at the same time, this development will be problematic if it is not accompanied by a program, control, and supervision. The main reason is that, due to the correlation between the real and financial sectors of the economy, macroeconomic shocks can broadly spread to the financial system or spillover from the financial sector to other macroeconomic sectors. The key purpose of this article is to answer two questions. First, whether exchange rate shocks affect Mutual Fund return, while they typically use diversification policies to reduce market risks, second, how much is contagion between different mutual funds, In other words, how much systemic risk Index affects from rate change shocks. we examine the correlation structure of daily net return of the mutual fund portfolios during the period from March 21st, 2011 to December 22nd, 2015, Applying the multivariate GARCH model. The results indicate that coefficients of exchange rate change shocks are significant just only some of the Mutual Funds, while contagion between mutual funds causes direct effects of shocks to Spread among Mutual Funds and increase systemic risk Index among Mutual Funds, and also a potential systemic risk.

In the real world, dispersion of suppliers and demanders prevents market formation. Kidney market is a true example of such markets that is not formed due to thin features. To tackle the problem, one needs to design a mechanism that can both revive the market and ensure the most efficient supply-demand matching. A matching is efficient when no other matching can allocate agents to a better place, or cannot strongly allocate an agent to a better place. To this end, the mechanism should be designed to allocate agents to their highest preferences, so that agents cannot make another better choice. In this study, information on 20 patient-donor pairs was recorded at a clearing house in Hamedan province in 2016. After processing data, the patients’ preferences were ordered in terms of matching blood group, illness period, donor’s age, kinship relationship with donor, and gender of donor. Then, a mechanism was designed to match 17 patients with the most efficient kidneys. When patient ith matches donor ith and registers at the clearing house, the mechanism can offer her/his the most efficient kidney. If a given patient finds a donor better than his/her peer donor, then he/she will leave his/her peer donor. Otherwise, he/she matches her paired donor.

This article determine the monopoly power of 22 food industries among 136 manufacturing industries at 4 digit ISIC level, and also determine the position of food industry in terms of market power dispersion among 23 fields in industry at 2 digit ISIC level. The unstructured and parametric approach of Lu and Yu was used to estimate the monopoly power of industry. According to the results, the mark-up of 73 percent of food industries is more than 10 percent. Industrial production of bread and a variety of beverages are the largest monopoly power, while industries such as production, processing and preserving of meat and meat products; manufacture of vegetable and animal oils and fats; manufacture of dairy products; manufacture of grain mill products show a competitive behavior. On the whole, 87 percent of the Iranian industries have monopoly power and uncompetitive behavior. Meanwhile, the industries have the decreasing average of returns to scale and the position of food industry in terms of inequality rank of market power dispersion, is 12 among 23 industries with 2-digit level. Therefore, using the potential capacity of some industries such as flour production can be helpful, with liberalization the exports of their products while no subsidization is provided for the raw material. In order to increase the competitive nature of the other industries, a strategy can be; reducing and rationalizing the import tariffs with the aim of improving competition.

Search and matching theory has not been investigated quantitatively In Iran’s economy. In order to do this work, we provide estimations of job-finding rate and inflow to the unemployment rate for Iran’s economy. For the first step, we calculate the probability which an unemployed worker finds a job and also the probability which an employed worker loses his or her job. In the next step, we estimate the two rates which are mentioned with using the calculated probabilities. The data are quarterly, and the study period is from 1384-1 to 1393-2. We use Mathematica 5 for estimating these rates. Finally, we find that both rates are important in fluctuations of unemployment. Furthermore, the rates’ values are less than the values estimated for other countries.

One of the most critical market duties is to ensure coordination between the supplier and demander. When the market fails to fulfill this duty efficiently, it either does not form or fail and disintegrate. This is because the number of market participants is either too large or too small, and/or the market experiences conditions where the participants scarcely give voice to their priorities with ease and confidence. Economists contend that the fundamental challenge in market design is that we sufficiently understand complex markets and develop our abilities to the point where we can reconstruct or redesign them upon their failure and/or use market-like mechanisms. When the process of price adjustment is slowly at work, economic factors tend to select what they want in the price they observe. Still, many markets are by far beyond this simple economic rule. In such markets, we may not readily obtain what we need even when we can afford it. In other words, while to want to and to be able to (to want a product and to be able to pay for it) generate demand in common markets, these two factors do not necessarily present us as customers in the complex markets since commodities are offered with variable qualities so that it is impossible to form a market for them. Some markets are so complex that people cannot select what they need despite their willingness and ability to pay for it. That is, price mechanism and automatic adjustment do not provide the market with balance although this does not imply the impossibility of market formation. . Market design theory and matching theory seek to provide a stage where suppliers and demanders can meet without using the traditional market mechanism (price mechanism). In this theory, price mechanism does not offer solution to the problem of resource allocation. Rather, allocation is based on suppliers and demanders’ conditions. Based on the proposed algorithm, ranked preferences replace and act as price system. One of the most important applications of market design in the past decade has been to the kidney and body parts market. for the purposes of market design, one should employ an algorithm that can overcome the causes of market failure such as returns to scale, externalities, uncertainty, thinness, congestion and insecurity to demonstrate preferences.These factors affect both market failure and lack of market formation.
The present study aimed to address the problem of kidney market and provide a solution to the problem. Dispersed market participants, limited number of suppliers and demanders, and poor supplier-demander relationshipmay lead to market (kidney exchange mechanism) failure or impede market formation.
In order to resolve this deficiencies we should design a mechanism for overcoming the market failures in order to reach to an efficient and stable allocation. Kidney market is a true example of this type of markets. Therefore, it is suggested to create a clearing room in which the information of kidney donors and patients be recorded and after processing this information and determine patient preferences, the matching algorithm could match the compatible couples(donors and patients)þ and kidney exchange can be facilitated. The present study was carried out in Hamedan Province in 2016 using matching theory which is a subset of market design and mechanism design. To this end, the information for fortyþ people , twenty of them patients and twenty others Kidney donator were recorded in the clearing room. Then, after blood and tissues tests and determining patient preferences and forming matching algorithms, seventeen of twenty patients could receive kidney transplant. However, without using this mechanisms only nine patient could have received transplan, Also using this mechanism will result at least 163817796 Rials per patient.

The aim of this paper is introducing a new method to estimation monopoly power and uses it for 136 Iranian manufacturing industries at 4 digits ISIC level during 2005-2013. The method used is stochastic frontier approach. The results indicate that the markup of nearly 98 percent of manufacturing industries is between 10 and 40 percent and they have an uncompetitive behavior. The average industries markup in Iran had a rising trend over time, reducing their average returns to scale. According to the results; there are suggested canceling the exclusive advantages that used to grant to some industries, lowering the tariff for increasing foreign competition with implementation necessary standards in order to production, importing industerial outputs and expanding industerial activities in the form of cooperatives.

One of the main issues and challenges of managing health care system in Iran, is the issue of inequities in access to health services. Theoretical studies and empirical evidences indicate that implementation of the referral system and family physician plan is one of the main strategies to overcome inequity in the health and appropriate using of scarce resources in this area. But for successful execution of the family physician, it is necessary to identify important determinants affecting the decisions of participants in this plan using scientific methods and studying, and health policy makers should design a program pack that matches preferences of the target population to increase the possibility of its successful implementation. This study used Discrete Choice Experiment (DCE) to identify important determinants affecting the decisions of physicians.
Results show that increase in net payments to general practitioners, nearer workplace to residence, allocation of quota to get the degree of expertise, existence of housing facilities and deadheading pay, less covered population and paying to physicians in less period of time may increase the utility and satisfaction of physicians and therefore, possibility of their participation and entry to the plan, as expected.
According to the results, the attribute "place of work" are significantly more important than the other attributes.

The various types of unemployment have been key subjects of economics from the past periods. Sometimes, unemployment is the result of improper distribution of labor force. According to the statistical data, medical labor market in Iran is faced with such a problem. The density of medical labor in metropolitan areas is high. As a result, this market is of supply surplus. On the other hand, Iran’s towns and suburbs experience demand surplus. This type of unemployment indicates a kind of market failure, which needs to design a market as a solution. Market design as a subset of game theory requires developing through collaborative efforts of a wide range of specialists. In this article, we analyze medical labor market using the matching theory as a subset of market design. This theory is a main subset of market design theory. We apply a hypothetical market; provide a model and present suggestions to amend the medical labor market in Iran.

Despite the relative success of the health system and the promotion of health indicators over the last two decades، Iran''s health system still faces serious problems. One of the most important of them، is the inequity in access to health. Theoretical studies and empirical evidences indicate that implementation of the referral system and family physician plan، is one of the main strategies to overcome inequity in the health and appropriate using of scarce resources in this area. In order to successful execution of the family physician، it is necessary، in addition to reform some known problems، the important factors influencing the decision of participants in the project have been identified by using scientific studies and methods and policy makers develop a package that is designed with maximum compliance to the preferences of the target population in order to increase the likelihood of successful implementation. This study is conducted for this purpose. The results indicate that،the visit،behavior of physician، the time of examination has been spent by doctor and being on call are attributes that influence the decision of citizens to enter to family physician. As we expected، increasing in visit، reduces the willingness to entrance to plan. The respectful behavior that given by the doctors، spending the appropriate time for patients and being On-call، increase the utility of citizens and the probability of their entrance to plan. The willingness to pay for behavior of physician،the time of examination and the attribute of On-call are estimated respectively 9579، 9947 and 3750 Toman.

Reasons of the fair wage occurrence, needs to the benefits of improvement of productivity, working relationships organizing, reduce of conflict and Effects of unjustified& unfair inequality of Wages was explained. In addition to analytical & descriptive methods, this paper exploited the results of the qualitative interviews, and questionnaire between representatives of workers and employers, and academic experts (using the EXCEL and SPSS17 software) and it is specified that With regard to the labor market on wage equality with the marginal product of labor is not clear,So for gaining fair wage benefits and prevention of non-paid loses, we should consider all aspects of the fair wage concept and explanation of it.

From a long time ago، predicting of financial crisis has been one of the most important concerns of economists and financial economics experts. In the first section of the present research، based on analyzing the fluctuation of rate of change of 10 Macro. variables during the period of 1358-1391 in Iran''s economy using Static and Dynamic، Variance and Semi Variance، and based on «Self-Organizing Map» neural network model، the exact years of financial crisis in Iran'' economy have been determined. Through the second section، using the «Feed Forward» neural network model، the future value of the rate of change of Macro. variables during 1392-1395 in Iran''s economy have been predicted، and finally via the third section using the «Pattern Net» neural network model and based on results of two previous sections، occurrence of financial crisis in the years of 1392-1395 has been foretold. Based on final results of the present research، it can be indicated that the financial crisis which has been occurred in the year of 1391 in Iran'' economy، which is the consequence of occurrence of financial crisis in1389 and 1390، will be continued in to the year of 1392; however، it will be evaporated gradually during it and the years of 1393 and 1395 are the years without financial crisis; albeit the model is indicating some early warning signals due to the return of crisis to Iran’s economy at the year of 1394.

Today، one of the approaches that in various domains such as health care policy is adopted، is that decision makers in the process of making and implementation of policies، try as far as possible، to consider the preferences and desires of the target population. Therefore، efficient and effective policy design and delivery of health services requires adaptation of their goals to the preferences of the society، which needs knowledge of health policy makers about population’s preferences and their valuation of health programs. Discrete choice experiment (DCE) is one of the best ways to identify the preferences of the population and valuation of outcomes. Because of little knowledge about this approach in iran and limited application of DCE in internal studies especially in the field of health policy، in this paper we emphasis on the reasons of the importance of using a DCE in the health economics and their theorical foundations and applications. We believe that، one of the requirements and prerequisites to successful implementation of the family physician in iran، is the knowledge of policy makers about preferences and desires of participants in this program، i. e. GPs and citizens. Such knowledge، along with other necessary conditions، such as Financing and provision of necessary infrastructure، significantly increases the probability of successful implementation of the scheme.

During previous years, Iran’s economy has been faced with numerous fluctuations, while in some cases it turned to a financial crisis as that of 2011-2012. However, the main question is that whether the financial crisis during 2011-2012 has been similar and predictable based on previous financial crises of Iran’s economy. In the present research, firstly, based on previous studies in the subject of Iran’s financial crises, the years of financial crises in Iran’s economy during years of 1978-2012 were determined. The corresponding results have indicated that three kinds of financial crises including Currency Crises, Money Crises and Twin Crisis (simultaneous Money and Currency Crisis), were occurred in Iran’s economy during 1979-2008. Then the financial crisis periods (in which two or more financial crisis years are included) were determined, the political and economic events during each of them were expressed and the reasons of occurrence of financial crises in each of them were described. Then the data of 10 macroeconomic variables of Iran’s economy belonging to 1978-2012 were deployed. Based on data of 1979-2008 as input data and information about crisis and non-crisis year and special kind of financial crisis in each crisis year as target data, the LVQ model was trained, in order to learn crisis and non-crisis patterns (behavioral patterns of macroeconomic variables in crisis and non-crisis years), and to learn to recognize the various kinds of crisis patterns (to understand which kinds of financial crises has been occurred in each crisis year). Then the trained model (trained model based on data of 1979-2008) was simulated using the data of 10 macroeconomic variables of Iran’s economy during 2008-2012, in order to access the capacity of occurred financial crises of years of 1979-2008 to explain and predict the financial crisis of Iran’s economy during 2011-2012. The results of simulation process indicated that the financial crisis of Iran’s economy during 2011-2012 has had a completely different kind of crisis pattern, compared with those patterns which have occurred in Iran’s economy during 1978-2012.

Given the lack of comprehensive explanation about the factors affecting the fair wage. This paper uses the analytical and descriptive method, explaining the eight components of the labor force characteristics that affect the determination of fair wages. In order to find the priority to those components: interviews with representatives from labor groups, employers, and academic experts were held in Iran. Thus, it became clear that to achieve fair wages, paying attention to all the features of the labor force is necessary. In other words besides the marginal product of labor (which has the third degree of importance), skill level, creativity, level of education as a sign of intelligence, duration of work or experience, seniority and responsibility in the work hierarchy should be taken into consideration as well. It should also be mentioned that workers and employers have different priorities towards each of the above mentioned components. So it is necessary to set up institutional settings to fill the gap between them.

Given the role of general practitioners in the family physician plan, it is important for policy makers and planners to know the factors influencing GP's decision to enter this plan. The purpose of this research is to extract preferences and factors affecting the decision of the physicians working in health– treatment centers affiliated to Tehran University of Medical Sciences. This was an applied descriptive survey. In this study, the preferences of general practitioners affiliated to Tehran University of Medical Sciences have been extracted. For this purpose, a discrete choice experiment was used. Data were collected through a questionnaire structured by D-Efficiency criteria using SAS software, designed by SPSS software, and analyzed by STATA12. Higher net income, employment in the place of residence, presence of a specified quota for PhD degree in family medicine, presence of housing and transportation facilities and lower covered population are preferred by GPs working in public sectors affiliated to Tehran University of Medical Sciences. Among these attributes, service place was found to be 2 to 6 times more important than others. The attribute of settlement period did not show to have a significant affect. The importance of some attributes showed to be different in different socioeconomic groups. Designing the program with regard to the demographic characteristics of GPs can increase the probability of their entry and successful implementation of the the project. Moreover, given the high importance of the location of employment attribute, it seems that very attractive incentives should be considered to encourage general practitioners in the public sector to practice in remote areas.