فصلنامه پژوهشهای اقتصادی (رشد و توسعه پایدار)
سال یازدهم شماره 3 (پاییز 1390)

Energy is aconsidered as one of the major inputs of production along with other inputs such as labor and capital that contribute to the production process. Moreover, most energy sources have fossil origin and are irreversible, so on the one hand, the basic features of the finitude of other energy inputs to production are distinct and the necessity of energy saving and the possibility of substituting them with the renewable forms are self-evident. Industrial energy demand analysis has always been one of the leading fields of research in economics. This issue is more critical in the case of developing countries, especially those with transitional experiences. In this paper, third generation of dynamic factor demand models for the Iranian manufacturing industries is estimated to analyze the speed of adjustment in factor demands. Using the quadratic functional form, this result was the elimination of energy subsidies in the short term which has a great impact on the industry to reduce energy demand. But, it is believed that in the long run, the intensity of this effect will be diminished. Furthermore, the results show that the speed of adjustment in capital stock of factory industry is very low.

Armington elasticity measures the degree of responsiveness of relative demand of an imported good to its domestically produced one, to relative home produced-imported price ratio of that good. In fact, it shows the competitiveness (or its substitutability) of domestically produced goods with respect to the imported ones. These elasticities were estimated for 23 selected goods (because of data deficiencies) at 2, 3 and 4 digits of ISIC classification and found them (for 19 goods) positive and statistically significant.

An autoregressive distributed lag (ARDL), approach to cointegration analysis is used to study the short- and long-run determinants of housing investment in Iran over the period of 1375:3-1385:4. The explanatory variables include house price index, construction cost, household income, money supply, bank’s deposit interest rate, exchange rate, stock price index and gold coin price. The short and long run results indicate that house price index, household income, exchange rate and money supply have positive and construction cost and stock price index have negative effects on housing investment. However, the housing investment is not affected by gold coin price and bank’s deposit interest rate. This research also indicates that the eslasticities of housing investment with respect to house price index, construction cost, money supply and household income are greater than one. However, it was found to be inelastic with respect to other variables.

For the first time, this paper analyzes the portfolio selection theory in the presence of housing market in Iran. One of the important theories about the housing price is household portfolio theory. Based on the theory, housing business cycles have determining effect on housing share in portfolio. For this purpose, a set of assets data consisting stocks, exchange, gold coins, bank deposits, bonds and housing over the period 1991-2006 are used. After calculation of returns, risks and correlation coefficients of assets over the period using Mean - Variance Model and MATLAB software, a combination of household assets in the portfolio have been extracted. The model, through simulating and supposing different weights for each asset determines an optimal combination of assets in portfolio based on risk classification of households: low risk, medium risk and high risk. Then, they are thoroughly examined to explore: whether the presence of housing asset in the portfolio can improve its risk, return and the composition of assets? Efficient frontier which covers all portfolios is also extracted. The results reveal that housing is an important asset in the portfolio during the housing boom period and causes the efficient frontier transmission move outwards.

Using Haskel theory, in this paper the main factors of change in wage ratios of agricultural and non-agricultural labor force are explored. Theoretically, the wage gap between these two sectors is explained by the gap between price and the one between TFP of these two sectors. In recent years, the wage gap between the two sectors has been decreasing in Iran. The international trade model (Haskel model) has been used in this paper and the results reveal that the major factor contributing to wage gap is the price one. The TFP is considered insignificant for wage gap. Mainly, the reason for increasing agricultural product index price, compared to that of non-agricultural index price has been government protection of agricultural products during these years.

According to exchange rate pass-through models, exchange rate has a great impact on the competitiveness of exports and determining the effects of exchange rate on export prices can be useful in planning for export promotion. For this purpose, in this paper it has been attempted in the theoretical framework of exchange rate pass- through models and applying ARDL approach the effects of exchange rate on non- oil exports price of Iran during 1971 to 2007 has been tested empirically. The findings show that there is a significant positive relationship between exchange rate and export price index so that by increasing exchange rate (devaluation of national currency) export price index increases significantly. Exchange rate pass- through to export prices is complete and to import prices in terms of destination currency is zero. In other words, the empirical results of this study indicate that in the Iranian economy, exporters are faced with devaluation of national currency (increase in exchange rate), which increases export prices in terms of domestic currency. Thus, the exchange rate changes have not significant effects on export prices in terms of destination currency and just affect the profits of exporters.

The convergence process and the advantages involved for less developed and developing countries, especially those located in the MENA region is of a great importance in economic studies. Through expanding regional co-operations and playing a wider role in the economies of the member states, it can prepare a suitable ground for growing regional markets and positive international economic reactions and finally can result into total development of the region. This article, using time series model is aiming at testing the convergence hypothesis in MENA region (15 countries) during 1980-2008. For analyzing time series model, we used Augmented Dicky Fuller test, Zivot & Andrews (with the endogenous time break) unit root test, Im, Pesaran & Shin and also Levin, Lin & Chu unit root panel data tests. The results of time series model with ADF and ZA tests show that there are two groups of convergence among the selected MENA countries. The first one is those countries which are converging from the low per capita income up to the average per capita income of the selected countries. The second one is the countries which are converging from the high per capita income down to the average of the region. The rest have diverged from the average per capita income during the period. According to Im, Pesaran & Shin and also Levin, Lin & Chu unit root tests, the convergence hypothesis of per capita income to average, is accepted for the whole sample. Altogether, the selected countries are minimizing the gap between their per capita income and the average per capita income of the region.