فصلنامه مدلسازی اقتصادی
سال هفتم شماره 3 (پیاپی 23، پاییز 1392)

Profit-sharing of the workers is a fairly way for the workforce which plays a vital role in efficiency and sustainable economic growth. Studying this subject by Islamic approach can be a new step. The supply and demand balance in the Profit-Sharing model will be analyzed from the perspective of Islam. In this paper, the data will be collected in libraries and the documentation analyzed by using content analysis. In addition, depended on Islamic economical principles, geometrical and mathematical means are used to explain the matter more reasonably. To investigate the equilibrium of labor share in the economy, firstly, the labor market equilibrium rent is investigated. Then, the effect of Profit-sharing model of Islamic Economics will be studied on the balance of labor supply and demand. The stability of the economy equilibrium in profit-Sharing will be expressed based on Islamic teachings. Finally, some results of profit-Sharing Model are described.

In this study, the existence of inflation persistent rate is examined in Iran. For this purpose, the degree of fractional integration is estimated by using GPH, Robinson adjustment, Reisen, Whittle, wavelets methods and consumer price index data of Central Bank during 1972-2010. The results indicate a persistent rate of inflation in Iran. The stationary and persistence of inflation rate indicates that, by a shock in inflation rate, its effects remains for a long time. This may be considered by economic decision-makers to select appropriate policies.

In this study, cardinal index of the age and welfare function elasticity are used to evaluate the social welfare compared to efficiency and inequality in Iran Provinces. The results indicate that Tehran, Bushehr, Markazi provinces have the higher welfare coefficient and Sistan and Bluchestan and Kurdestan provinces have the least rate of welfare in Iran. Also, the findings reveal that there are no significance relation between the rate of welfare and population in Iran provinces. So, it is proposed that the welfare index can be improved by increasing income in some provinces like Tehran, Isfahan, Khoozestan and Khorasan-e-Razavi, but by the reduction of inequality level in some other provinces such as Yazd and Hamedan.

This paper studies the relation between inflation rates and its uncertainty by using Markov-Switching regression model and monthly data of consumer price index during 1990:01-2012:09 in Iran. Inflation uncertainty is estimated by using Generalized Autoregressive Conditional Heteroskedastisity (GARCH) model. The empirical results of Markov Switching Auto Regressive (MSAR) model represent the presence of two clearly differentiated regimes over the entire Sample. The first regime corresponds to a high level inflation rate, low volatility, and the second regime corresponds to low level inflation, high volatility. The use of Markov-Switching Regression Model indicates that the increase of inflation rate will be associated to higher uncertainty according to both regimes.

In this paper, by using the nonlinear model of Hamilton Markov switching, the possible features of circular pattern are considered in Iran by a seasonally adjusted real GDP during 1988-2008. The results represent that business cycles extracted from Markov switching method are more appropriate than the linear model and the growth rate of GDP divided into three regimes by the average of negative, mildly positive and high positive growth as 3.92, 4.43 and 9.53 respectively. Iran economy experienced, during the above period, 7 seasons of recession, 10 seasons of mild growth and 58 seasons of high growth. Furthermore, the probability of stability in recession, moderate, and high growth are estimated 0.3, 0.92 and 0.5 percent respectively.

Exchange rate known as a strategic variable plays an important role in the economy, because of affecting on different sectors in economy all over the world. So, exchange-rate predictions have always been an important subject for the researchers in Economics. This paper tries to study the attributes of exchange rate developed by monthly official data of Iran Stock Exchange based on Smooth Transition Autoregressive (STAR) models. The result of simulation based on STAR models and estimated by Genetic Algorithm method, outperforms linear time series models, such as ARIMA out of sample predictions based on RMSE, MAE and DA criteria.

Dust storm has made massive loss in west and south provinces of Iran during 2000s. In this study, the damages or losses caused by dust storms will be evaluated in the economy of highly vulnerable regions including Ilam, Khuzestan and Kermanshah during 2006-2011 using parametric methods. The total economic losses of agricultural productions in these provinces has been estimated about 2,227 million dollars under the conditions of the first scenario and about 13,361 million dollars under the conditions of the fourth scenario. In 2009, each day off caused by dust storm in three provinces officially announced by local government has totally made 142 million dollars loss based on provincial value added and 66 million dollars loss based on average national value added. Following up the natural rights of citizens through regional and international organizations, implementing the crisis management, encouraging Iraq government to control the dust centers and supporting completely the economic actors, especially the farmers in provinces affected by the dust storms are recommended to solve the problem.