اقتصاد مقداری

امروزه ضرورت بهره مندى از فناوری هاى به روز، در جهت صنعتی شدن کشورهاى در حال توسعه که قصد رقابت و ورود به بازارهاى جهانى را دارند بیش از پیش افزایش یافته است. کالاهای وارداتی با فناوری بالا که به عنوان یک متغیر جانشین برای اثر سرریز تحقیق و توسعه و انتقال فناوری می باشند، موجب افزایش سطح دانش درکشورهای در حال توسعه می شوند. این امر موجب افزایش سهم صنایع مبتنی بر فناوری های پیشرفته در تولید ناخالص داخلی و رشد صادرات آن ها می شود. پژوهش حاضر به بررسی تاثیر واردات و صادرات صنایعی با فناوری بالا بر روی رشد اقتصادی ایران در طی سال های1390-1380 پرداخته است. از داده های فصلی در قالب مدل خود بازگشت با وقفه های توزیعی (ARDL)، در جهت بررسی رابطه بین متغیرها مورد استفاده قرار گرفته است. نتایج حکایت از تاثیر مثبت و معنی دار واردات و صادرات صنایع با فناوری بالا بر روی رشد اقتصادی ایران دارد. همچنین، اثر متغیر های موجودی سرمایه، اشتغال و هزینه های تحقیق و توسعه بر روی رشد اقتصادی ایران مثبت و معنی دار بوده است.

Stocks and houses as two major assets which play important role in the balance sheet of Iranian households. Changes in two markets have a large influence on wealth and the general economy. The purpose of this study is to examine the relationship between stock and house prices over a thirty-year period using vector auto-regression (VAR). Using yearly data for the period from 1985 to 2013, we conducted a Granger-causality test and Impulse response functions (IRF). The causality test is performed with control variables and the results supply evidence on the bidirectional relationship between house price and stock price. Impulse response function is estimated in order to investigate the size and timing of the causality. The IRF concludes that, when the impulse is stock price, the every response of house price is most positive and the values fluctuate around the line zero at each time period. .

یکی از مهم ترین اهداف اقتصادی برای کشورها تقویت رشد اقتصادی است؛ بنابراین شناخت عوامل موثر بر آن از اهمیتی زیادی برخوردار است. به دلیل وجود بی ثباتی شدید در درآمدهای نفت در ایران، استفاده از سایر درآمدها مانند مالیات در تحقق هدف فوق مهم است. با توجه به وجود نوسان در سیاست های مالی ازجمله مالیات ها، شناخت اثر این نوسانات بر رشد می تواند در جهت دستیابی به اهداف بلندمدت رشد کمک کننده باشد؛ بنابراین مطالعه حاضر به بررسی اثر نوسان درآمدهای مالیاتی بر رشد اقتصادی ایران برای دوره زمانی 92-1350 با استفاده از روش EGARCH-ARDL پرداخته است. نتایج نشان داد که اگرچه نوسان درآمدهای مالیاتی دارای ضریب منفی بوده و در بلندمدت و کوتاه مدت اثر معناداری بر رشد اقتصادی ندارد اما درآمدهای مالیاتی در بلندمدت دارای اثرمعنی دار بر رشد و در کوتاه مدت فاقد این اثرگذاری است.

عدم تشخیص حباب های قیمت دارایی و نوع آن (یگانه و چندگانه) موجب اثرات مخربی بر اقتصاد می شود. ابزارهای اقتصادی جدید، نه تنها تحلیل رفتار انفجاری ملایم حباب را ممکن گردانیده؛ بلکه تعیین تاریخ شروع و خاتمه آنها را نیز مهیا کرده است. هدف مطالعه حاضر کشف حباب های قیمت بورس اوراق بهادار تهران و شرکت فرابورس ایران و تعیین تاریخ های شروع، انفجار و محو کامل حباب در دوره 01/1389 تا 01/1395 است. در این راستا از شاخص کل، شاخص صنعت، شاخص50 شرکت و شاخص کل فرابورس استفاده شد. نتایج تحقیق نشان دهنده آن است که بازار بورس 2 دوره حبابی و فرابورس 5 دوره حبابی را تجربه کرده اند. نتایج همچنین نشان دهنده این است که بازارهای بورس و فرابورس به ترتیب در 59% و 57% بازه مورد مطالعه حبابی بوده اند. به عبارت دیگر در بیش از نیمی از دوره مورد بررسی، حباب وجود داشته که بیانگر بی ثباتی زیاد قیمت های سهام است.

Investment in education and health sector, as human capital, has an important role in economic growth and its enhancement in many countries. Lots of studies have been carried out in this field; however, the effect of simultaneous analysis of education and health, as well as the private and state sectors in economic growth of Iran has not been investigated. Thus, in the present study mutual relationship between private and state educational and health care expenditures with the economic growth of Iran from 1965 to 2014 has been surveyed. Therefore, in the present paper variables were tested by using Integration Adjusted Dickey – Fuller test. Then for choosing appropriate causality test, the co-integration between variables was tested by ARDL method. Then, by using Granger, Toda and Yamamato causality tests, the two ways causal relationship between variables was assessed. First, findings showed a lack of long-run relationship between variables. Second, the results of causality tests indicated that there is no causal relationship between private and state educational expenditures with economic growth because educational system faces serious problems such as discordance between the educational system and needs of society and labor market. Also, the obtained results delineated that there is no causal relationship between private sector and state sector health care expenditures with economic growth.

Abstract Negative binomial regression model (NBR) is a popular approach for modeling overdispersed count data with covariates. Several parameterizations have been performed for NBR, and the two well-known models, negative binomial-1 regression model (NBR-1) and negative binomial-2 regression model (NBR-2), have been applied. Another parameterization of NBR is negative binomial-P regression model (NBR-P), which has an additional parameter and the ability to nest both NBR-1 and NBR-2. This paper introduces several forms of bivariate negative binomial regression model (BNBR) which can be fitted to bivariate count data with covariates. The main advantages of having several forms of BNBR are that they are nested and allow likelihood ratio test to be performed for choosing the best model, they have flexible forms of mean-variance relationship, they can be fitted to bivariate count data with positive, zero or negative correlations, and they allow overdispersion of the two dependent variables. Applications of several forms of BNBR are illustrated on two sets of count data; Australian health care and Malaysian motor insurance.

The present study investigated weak-form market information efficiency in Tehran security exchange (TSE) as an emerging market and in Dow Jones United States security exchange (DJUS) as a developed market based on random walk model. In each market, the random walk model was examined using daily and monthly returns of a set of indices. The results of the parametric and non-parametric tests indicated that the daily returns are not independent and identically distributed in TSE. Moreover, according to the results of the variance ratio test, a trending behavior in daily returns and mean-reversion behavior in monthly returns were observed. In DJUS, however, the daily returns were found to be independent and identically distributed and the results of variance ratio test did not confirm that the returns follow a particular pattern in this market.

Social capital is one of the most important subjects in development economics. It has a crucial role in development process in developing countries. To the best of our knowledge, there is no study about the importance of government size in social capital. Therefore, the purpose of this paper is considering the relationship between government size and social capital in 109 developing countries during the period of 2008-2014. To do so, we have used a panel data method based on the model of Knack and Keefer (1997). Estimated Results of a fixed effect panel model indicate that there is a non-linear relationship between government size and social capital. When the government size is small (the government size is less than 26.17%), increasing government size has a significant positive impact on social capital. However, when the government size is large (the government size is larger than 26.17%), government size has a significant negative impact on social capital. Before this threshold level of government size, due to preparing safe environment as well as social and economic institutions, ensuring property rights, providing public services as well as social security, building schools and universities, etc., expanding government leads to promoting social capital. But after this threshold level, because of inefficient expenditure, corruption and crowding out private investments in social capital, expanding government has a negative impact on social capital.  

This paper examines the non-linear relationship between CO2 emissions and economic development using an innovative dynamic panel threshold technique. The sample consists of 35 developed countries over the period 2003-2010. The empirical results indicate that there is a threshold effect in the relationship between economic growth and pollutant emissions as suggested by the environmental Kuznets curve (EKC). In particular, at the early stage of economic development below the estimated threshold value, more growth deteriorates the environmental problems. However, after this threshold value further growth serves as a solution to the environmental problems. Accordingly, promoting economic growth and becoming rich in the long run, is necessary to solve the environmental problems arising from greenhouse gas (GHG) emissions. In the short run and in the early stage of economic growth, focus on investments in environmentally friendly technology and on the use of renewable energy is necessary for mitigating the pollution effects of economic progress.