فصلنامه تحقیقات اقتصادی
پیاپی 55 (پاییز و زمستان 1378)

In every society the optimal performance of economic system is depened upon two efJkient, powerful and administered sections: Real and Financial. The existence of different institutions in financial markets make different financial instruments available to real section. Investment companies are among active financial institutions which collect small amounts ofcapital by selling thier shares and invest them in profitable economic activities, especially securities of different companies. Investment companies invest in variety ofsecurities and shares with different risks and investment returns. Through diversification, they can reduce risk and increase returns of thier in vestors. Our question in this paper is that, are these comp anies able to do so? On the basis of this assumption, we studied the changes in risks and returns of in vestment companies' sharesfrom March 1996 to March 1998. The results showed that the shares of investment companies (except one or two of them) have low returns in coutrant to their risks Therefore the shares of these companies were suitable for risk-avertcrs. and risk-lovers could gain more hy investing in other shares. By using EGP model and maximizing subject to fixed risk . we found that an optimal portfolio combination contains 22 companies' shares with low risk and reasonable return. Comparing the investment compnnics portfolio in Tehran Stock Exchange wit h. this optimal portiolio shows that these companies have little shares in the optimal portfolio

Our review of the neoclassical model emphasizes that it is in fact not a model of ongoing growth, since it implies that per capita output nues will approach constant values in the absence of exogenous ( there fore unexplained) technological proKress. Several analyt ical results are exposited, Following this review, it is argued that the neoclassical approach not only fails to provide an explanation of everlasting steady - state growth. hut also cannot plausibly explain actual observ ed cross-country growlh rate:differences by reference to transitional (i.e., non-steady-state} episodes. It can, with the inclusion ofhuman capital inputs, explain a substantial portion ofobserved cross-country differences in income levels, but there are some questionable aspects of this accomplishment and, in any event, explaining levels is not the main task of a. theory of growth. The endogenous growth literature attempls to provide explanations for ongoing, steady-state growth. in per capita output values and consequently for growth rate differences across countries. Three types of endogenous growth models are presented, featuring (i) externalities resultingfrom linked capital- and- knowledge acdumulation, (ii) accumulation of human capital (i, e., individuals' workplace skills). and (iii) continuing growth in the stock ofexisting productive "designs," with the entire stock facilitating the creation of additional designs (that are produced in re.'ponse to private rewards). The last of these types seems most plausible as a mechanism capable of generating long-lasting growth. The likelihood o] obtaining steady-state (never-ending hut non-explosive) growth. from any of the models seems very small, however, since such a result would require highly special (zero measure) parameter values. The endogenous growth approach seems fruitful, nevertheless, as it con in principle rationalize long-lasting growtn and growth rate differences across economies and will indicate with reasonable accuracy the effects of changes in policy, tastes, of technology that alter the steady-state capiialllabor ratio

Government, now, more Than The Fist half of 20th Century, have accepted. reducing poverty as an inevitably and necessary object. Implementing poverty reduction programs would not he as succesful as, without paying enought attention to the dimentions of poverty. In this way Estimating poverty line and percent ofpoor people are of the most favorable measures. also we would he enable to make more precise decisions about objectives and. implemcntary approaches of Porerty reduction programs. And then it is vital for us to estimate fioncial needs of implementing poverty alleviation programs. We, In this research, focus on economic aspects ofporerty reduction proigrams and estimate extent of poverty, determine objectives of reducing poverty program, and a Tlast estimate financial needs of the objectives

Since resdential units are not homogeneous Commodties and diffirence in characteristics such as: Size of the land, squaqre footage of constructed part , kind of materials being used, and neighborhood. lead to dijferentiation of housing units, applidation of regulardemand junction of for Such a commodity Would seem rather absrtact. To make hie demand junction more realistic, in this paper "Hedonic approach is being used. In Order to implement this approach, first it is assumed that price of housimg units are ajfectds by Two general categories ojCharacterisrics namely Phycical and neighgorhood factors. Using questionnaires, data in the form of cross section has been collected and the hedinic price funtion, using OLS, has been estimated. Having obtained the estimated. Our Findings Show that for the city of Khomeini - Shahar' hoth groups of Physical and neighborhood factors are affeted by implicit prices of the ch.atacteristixd being chosen, imcome, average age of the head of occupants, average education ofthe occupants, and the numher of residents of the unites.

After the appearance offinancial crises in developing countries, there has been a wide range of researches about the financial capacity of these countries with respect to their debts. Though this subject has been a matter of argument for several decades, today it is one of the most contravertial . arguments in economic literature. There are, in general, three factors which determine the income capacity of the governments: degree of development, sectoral composition of GNP, and the degree of openness of economy. But there is not a common agreemant in their degree of effectiveness. Later, other factors have been put to test, and with the help of advanced econometrics models have been developed more seriously. In spite of strategic importance of Iran and middle East area, still there has not been an independent research in this issue, so, in this article we tried to analyse the characteristics ofpublic income in Iran and factors affecting it.

This paper represents a theoretical model from which the supply function for a durable goods is derived. It turns out that consumer at the equilibrium condition equates its user cost with the marginal value of services received by using an additional unit of durable goods. The stock price is obtained from this condition. In addition, at the equilbrium condition for producer, the stock price is equal to the marginal production cost which results the supply function of durable goods. Since the fa ctors such as interest rates, depreciation rates, Wold of goods and the marginal value ofservecies determine the stock price, Thus they Life ime affect the supply function indirectly