فصلنامه مدلسازی اقتصادی
سال ششم شماره 4 (پیاپی 20، زمستان 1391)

This paper investigate the asymmetric effect of oil price shocks on economic growth in OECD and OPEC countries with emphasis on the setting of shocks and regime changes during 1972-2011. The results indicate that the role of oil price shocks on the development price uncertainty is asymmetric in world markets and the shocks formed in this setting have asymmetric effects on the economy in both groups. But, the asymmetry in the OECD countries and the effects of OPEC, are greater. Of course, the impact of shocks increase when occurred after a stable period of oil price. Furthermore, a shock which influences positively a group (OPEC or OECD), has negative impact on the other group.

The aim of this article is the study of the effects of fiscal shocks on GDP and thelevel of price in Iran, using a quarterly dataset of variables during 1988:1-2010:4.This analysis will take place by using a Structural Vector Auto regression Approach.The results of impulse response functions show different components of government expenditure and tax revenues as having different impacts on economic variables in the short term and long term. A positive shock in total government expenditure and government current expenditure is found to have positive temporary effect on output and also increases the level of prices in the short-term, while the government investment expenditure has more stable positive effect on GDP and no significant effect on prices. Total tax revenue expansionary shocks do not affect the GDP but impose a negative effect on the level of prices in the short-term. Investigation of tax revenue components shows that direct tax shocks contribute to the decline in output and the level of price in the short-term and Indirect taxes has no significant effect on these variables.

Financial markets tendency to a sudden shift as a result of changes in the investor behavior can lead to the appearance of different regimes of the price and returns in these markets. This paper, the switching behavior of different regimes in Tehran Stock Market will be investigated through returns (TEDPIX) indexation Switching model during 2006-2011. The results represent that there are 3 positions or regimes for this market. One has a negative return average and two others have a positive returns average. Also, the stability of the regimes has a positive but low returns average and the change of other regimes to this one is of high probability in this market.

This paper introduce index numbers theory emphasis on economic approach and its applied welfare of consumer behavior. Price index number theory, product and welfare are one of the most important debate in economics while expand changes index numbers theory has been experienced in last three decades. These changes can be related to views differences of economists to index number theory. Some economists calculated welfare measurement and welfare changes with relating to demand system like Linear Expenditure System (LES) and Almost Ideal Demand System (AIDS). In this paper, True Cost of living Index is estimated by using AIDS. The Results indicate that the Cost of Living Index in rural area is larger than urban during 1997-2007.

This article investigate the export comparative advantage of Iran and the 11 major exporters using the Revealed Symmetric Comparative Advantage (RSCA) index from 1995 - 2008. The values of the index were calculated by the data derived from the Food and Agriculture Organization (FAO) website. According to the results, Syria, Iran, India, Turkey, Singapore, Egypt, Morocco, Bulgaria and Vietnam have comparative advantage and Canada and Germany don’t advantage. Also, China has export comparative advantage in some years. Although Iran has a comparative advantage in the export of selected medicinal plants, but its export competitiveness trend is declining. On the other hand, the analysis of Iran's competitive position in the export comparative advantage of selected medicinal plants compared to the other top exporting countries represents the demotion of the position from the third to the sixth in the world.

In this research, we will study the effects of different variables such as energy consumption, manufacturing products, foreign direct investment (FDI) and economic development on the emission of Co2 in D8 countries during 1990-2007 as an econometric model estimated by using Panel Data and GMM. The results represent that, in Fixed Effect method, all variables under the examination except FDI have a positive and significant effect on Co2 emission. In GMM, all variables estimated are positive and significant too.

Lower level of trade and non-trade barriers between different regions of a country raises the possibility of purchasing power parity theory and the law of one price within an intra-national context. Of course, it is possible due to economic and geographical conditions, the prices also be affected by local shocks. Therefore, it leads to the question "whether there is price convergence between different provinces and if any local shocks, what will be the half-life of convergence of provincial price indices? In this paper, we examine the convergence of the consumer price index across Iran provinces using panel unit root test and monthly data during 2002-2011. The results indicate that the convergence of provinces price indices depends on the choice of the numéraire province and by deviations from the law of one price based on a local shock, the convergence of half-life would be about 1.5 years.