فصلنامه پژوهش ها و سیاست های اقتصادی
پیاپی 63 (پاییز 1391)

The impacts of market structure on productivity, having been studied through a variety of mechanisms, can be analyzed by using the factors related to market structure and productivity. This paper, studies the relationship between market structure and productivity in Iran's manufacturing sector, during 1995 – 2007. The results show that market competitive structure has positive effects on productivity but adverse effects on the growth of productivity. Monopoly structure and its profitability improves productivity growth by encouraging the firms to make investment in R&D. In monopoly industries the net entrance of firms produces positive effects, while in the competitive industries it results in negative effects on productivity growth. During the boom time, the growth of productivity in competitive industries, due to further entrance of firms, decreases, but in monopoly industries it increases which is the result of encouraging the firms to make investments and expand their market size. In addition, for both monopoly and competitive structures, imports enhance productivity growth by encouraging firms to reduce their expenses and increase their profitability. Keywords:

This paper models the impact of supply and demand sides on real prices of housing in Iran. Household expenditure, number of households, user cost (housing ownership cost), bank loan, land price and construction cost are included in the model. Given the advantages of panel data, this paper uses unbalanced data of urban areas of 30 provinces of Iran during 1991- 2010. To segregate the impacts of the variables in time horizon, with regard to an Error Correction Model, the functions are estimated in short-run and long-run by the Dynamic Ordinary Least Squares (DOLS) method. Results indicate that both in the long-run and short-run, household expenditure, bank loan and land price had positive effects and ownership cost had adverse effects on real house prices. In addition, in the shortrun, the lagged house prices produced positive effects on the current real house prices.

Mutual funds, as financial instrument, are growing in importance in the Iranian financial market. This paper examines the risk-adjusted performance of 40 Iranian mutual funds in the course of 2010, using the traditional stand-alone performance measures: Jensen’s alpha, Sharp, Sortino and Treynor ratios, along with a nonparametric frontier model. The results indicate that the risk-adjusted performance measures produce extremely different results, regarding size, performance indices and ranking of mutual funds comparing the results of the models in which the risk is absent.

The Housing market has experienced fluctuations in recent years. The main factors for the soaring prices of houses are demand and speculative swings, originating from the structural problems of macro economy as well as galloping liquidity increase and incapability of other economic sectors and the capital market to absorb this liquidity. This paper studies the effects of liquidity on house price swings in Iran and 20 OECD countries which have experienced more house price fluctuations in recent decades. The estimates have been done for the years 1980 to 2009 by applying panel data method. The estimations for all selected countries were carried out first, and then the countries were divided into two groups: countries with oil revenues and countries without oil revenues. Results indicate that in both groups the liquidity has meaningful and positive effects on house prices, so considerable part of the house price volatilities can be explained by the liquidity which exists in the sector. Oil revenues play a meaningful and positive role in house price swings in oil producing countries, exerting an extra 36% of direct or indirect fluctuations, comparing the other group.

This study examines the deviation of concentration from its steady state level in Iranian manufacturing industries. The study is carried out for 94 industries based on cross- section method with four-digit ISIC code in the years 1999 and 2007. The coefficient of partial adjustment is significant and less than one. Therefore there is significant partial adjustment towards steady state level of concentration. The same results were obtained in subsamples including 47 industries with high advertising intensity and 47 industries with low advertising intensity. The comparison of Herfindahl Hirschman index indicates that the level of industrial concentration in the majority of industries (63 percent) has decreased during this period. The findings of the study support the Sutton the market size in exogenous sunk cost industries. But the result is not valid for endogenous sunk cost industries.

Charity is an Islamic tool for poverty alleviation and achieving justice. It also brings maturity and evolution to the payer of which and subsequently to the community. Due to its economic nature, it can be influenced by the economic and social variables. This paper estimates the effects of distress and volatilities of the markets on Charity. It's been tried to estimate the effects of some of the main economic variables on Charity: The Effects of variables of income (production) that reflect economic recovery, the number of the religious institutions which indicates the size of market, as substitutes for making Charity through Relief Committee, Unemployment and inflation, as signs of disorder in labor market and the market for goods and services, as well as the government expenditure that shows the injection to the society. Pooled data method along with econometric models has been used for the study. The data are for the years 1999- 2007. The results indicate that Charity is positively correlated with the provincial income per capita and the Governments spending while negatively correlated with the number of substitutes to charity organizations, inflation and unemployment. It also reflects the low elasticity of provincial per capita charity with the provincial per capita income as well as the number of religious institutes indicating that it is regarded as a necessary expense.

This paper studies the effect of fluctuations in interest rates on long-term bank deposits in Iran. Analysis of the data has been carried out using the model of Johansson and Jusilius Vector Regression (VAR) and the Vector Error Correction Model (VECM) during the period 1971-2007. The results are indicative of positive long-term equilibrium relationship between real interest rates and the volume of financial resources of the banks. They also reflect the positive effect of the increase of real interest rate on the volume of bank's funds. In addition that the real interest rate in the long-run has a positive effect on the volume of funds in the short-term model was confirmed.

The main purpose of this article is to study the impacts of terms-of-trade shocks on trade balance in Iran, using the HLM (Harberger – Laursen – Metzler) Effect theory. According to HLM Effect, an exogenous temporary increase in terms-oftrade of a small open economy leads to a temporary improvement in that country’s trade balance, but this effect fades away as time passes by. To study whether any systematic patterns exist in the responses of the trade balance, given to the termsof- trade shocks, a Structural Vector Auto Regression (SVAR) model has been employed. The variables used are terms of trade (unit value of export to unit value of import); Gross Domestic Product in constant prices and trade balance (net export to Gross Domestic Product) during 1959-2010. Our results approve the idea that there exists an HLM Effect in Iran's Economy.

Taxation as a main source of revenue for the government has always provoked some sensitivities in different societies. Tax revenues are considered to play an important role, through income redistribution, in the readjustment of income and wealth, improvement of economic and social justice and prevention of inequalities. Therefore, tax revenues are seen as a reliable and influential instrument to carry out government policies in response to economic crises. An efficient tax system is the one able to maximize tax collections. This is not going to be as easy as it appears, since a country's taxable capacity is a challenging issue. By definition, the taxable capacity is the tax that the society is able to pay. Estimating taxable capacity can, on the one hand, represent the tax efforts exerted in creating tax revenues and, on the other hand, it might be of help in determining the extent to which the tax authority can maximize their revenues. In order to capture the factors involved in taxable capacity and to present a method for measuring regional tax potentials, this research has confined itself only to Yazd Province. The variables such as "the share of value added of different economic sectors in the provincial GDP" and "the provincial rate of literacy" have been considered as the influential factors in the regional taxable capacity of this province and their impacts have been tested through an econometric method. By simulating the general form of "Luffer" curve, the researchers have shaped a second order function of tax revenues, tax ratio, and an estimation of the coefficients thereof, in order to determine the tax ratios that maximize the revenues and to calculate the maximum tax level to be collected. Research findings indicate that the variables "the shares of value added of different economic sectors in the provincial GDP" and "the share of the industry & mining sector in the regional GDP" can affect the overall regional tax ratio. The results also show that the optimal tax ratio in the region under discussion is 4.7 percent.