فصلنامه تحقیقات مدلسازی اقتصادی
سال چهارم شماره 13 (پاییز 1392)

The purpose of this study is to evaluate the impact of trade openness and economic globalization on employment. This study employs the Bounds test method and Autoregressive Distributed Lag (ARDL) model for Iranian economy during 1979-2009. Comparing with the other empirical studies، this study in addition to traditional index of trade liberalization as trade openness has been applied the new and more comprehensive economic globalization index as one dimension of the new KOF globalization index. This index includes the actual flows of trade such as trade، foreign direct investment and portfolio investment، and restrictions such as trade barriers and tariffs on actual flows. Also، the other control variables effective in employment such as GDP per capita، industrialization and government size has been considered. The results show a negative relationship between trade openness and employment but they show that the impact of economic globalization on employment is positive. Thus، it seems that the new economic globalization (KOF index) which is a broader comprehensive index is a better proxy of globalization.

This study examines the time series behavior of oil production for OPEC member countries in a fractional integration modeling framework. It’s aim is to identify the potential for structural breaks and outliers. The analysis is based on a monthly data from January 1973 to October 2008 for 12 OPEC member countries. The results indicate that a mean reverting persistence in breaks has been experienced in ten of twelve oil production countries. Thus; it is obvious that shocks affect on the structure of OPEC oil production and have persistent effects in the long run for all countries. In some countries is expected the effects to be permanent.

From technology، security and physical points of view automobiles are different; regarding Hedonic price model، price of a car is a set of implicit prices concerning different characteristics. In this article we estimate the Hedonic price models using 2009 Iranian automobile market data concerning different characteristics for small cars (Engine capacity of 2000cc and less) and large cars (Engine capacity of more than 2000cc): in Iran cars with engine capacity of 2000cc and less benefits from special petrol subsidies while this is not the care for the large cars. The results indicate that characteristics such as antilock brakes (including ABS and EBD)، width، airbag، fuel consumption and engine capacity for small cars، variables such as airbag، antilock brakes (including ABS and EBD)، and highs for the large cars are important from the points of view of Iranian customers and have significant effects on the car price.

Unobservable productivity shocks cause selection and simultaneity problems in firm’s decisions and these problems cause estimators such as ordinary least squares، have biased estimation for coefficients of production function inputs. In this study، data of five automaker companies in the period of 1383-1387 have been used and production function of car industry have been estimated by ordinary least squares، fixed effects، random effects، Olly and Pakes (1996) and Levinsohn and Petrin (2003a) approaches. The results show that fixed effects and Levinsohn and Petrin (2003a) approaches can’t be appropriate for the production function estimation of car industry. In other words، reaction of automaker companies to productivity shocks will not be done through adjustment in labor، capital and energy demands and there is no significant correlation between inputs adjustment and productivity shocks in car industry. But estimated coefficients of energy and capital in semiparametric، random effects and ordinary least squares approaches show that estimated coefficients of energy and capital in random effects and ordinary least squares approaches are upwardly and downwardly biased، respectively. These results are perfectly consistent with the viewpoint of Olly and Pakes (1996) about bias of traditional estimators and show that automaker companies، in response to the productivity shock، adjust their investment level. In addition based on estimation of semiparametric approach، output elasticity of capital and energy will be respectively 0. 82 and 0. 64.

Simple sum monetary aggregation approach that based upon perfect substitution of monetary components assumption is inconsistent with microeconomics theories. In this research، using quarterly data of Iran over period 1370:1–1388:1، we first calculate monetary aggregation based on divisia index for both measures of money (M1، M2) and then estimate the demand functions for money for divisia and simple sum monetary aggregations separately. The results show that the adjustment speed of divisia aggregations is more than that of simple sum aggregations and the demand functions for money that construct by divisia aggregations، are more stable.

Efficiency analysis plays an important role in price regulation in the electricity distribution sector. This paper analyses efficiency and productivity of 38 electric distribution companies in Iran from year 1387 to 1389 (Iranian calendar year) by using slack based model (SBM). Super efficiency analysis is employed to rank full efficient companies. According to results، Tabriz، Ahwaz and north Khorasan companies have best performance among others. To examine importance of losses inclusion as input on super efficiency scores، statistical tests are utilized. Results indicate significant difference in super efficiency scores with and without accounting for losses. Average productivity index of total companies has declined by 4 percent under investigated period. Further، Panel data analysis applied to specify determinants of super efficiency of electricity distribution companies. According to results، Loss rate، network density and transformer load factor are the main determinants of super efficiency.

In economic literature especially in international economic literature، the Harberger، Laursen and Metzler (HLM) effect is an important issue. According to HLM effect، deterioration in the terms of trade decreases GNP and then causes deterioration in the current account. The main idea of this study is the examination of HLM effect in Economy of Iran. We use annual data of current account، terms of trade and GNP as relevant variables. In this paper ARDL approach was applied for period (1978 -2010). The Banerjee، Dolado and Mastre and also Pessaran and shin cointegration test verified the equilibrium long run relation between our variables. In the other words the results of econometric estimation indicated a long run relationship between current account، terms of trade and GNP. According to these results، terms of trade and GNP have direct effects on current account.

One of the empirical relationships that have been used to study the dynamics of labor market is the Beveridge curve -the scatter plot of unemployment rates versus vacancy rates- that is used to summarize the state of that market. The starting point for deriving the Beveridge curve is a matching function between unemployed workers and vacant jobs. In this research، provincial data are combined to estimate the Beveridge curve and the matching function of Iran. The matching function is estimated using provincial data for the period 1993-2008 and for estimating the Beveridge curve، provincial data for period 2005-2008 are used. The outcomes imply that the number of unemployed workers and vacant jobs has a positive and significant relationship with successful job matches. The elasticity of matching function for the unemployed and job vacancies equals 0. 24 and 0. 79، respectively. The Beveridge curve depicts a convex and negative relationship between unemployment rate and vacancy rate، although the relationship is not strong.