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With regard to importance of investment as an engine of economic growth many economists such as Wicksel, Keynse and Harrod believe that investment is the main source of business cycles. Hence this study specifies investment function according to a basic macroeconomic model such as Ramsey model. Application of Ramsey model can help to extend macroeconomics with micro foundations in economy of Iran and prepares new scopes for researchers. The main idea of this study is specification of investment function according to Ramsey model and its estimation by cointegration technique for period (1990:Q1-2007:Q4). The result of econometric estimation indicated a long run relationship between investment, capital stock, and shadow price of capital, installation cost of capital, capital price and terms of trade. Results showed that capital stock, shadow price of capital and terms of trade have direct effects and, installation cost of capital and capital price have inverse effect on investment.

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The concept of “Innovation” has changed considerably in recent years. According to new theories, the innovation emerges in a system of interrelated elements and determinants during which the idea changes to a commercialized output or process. The literature on the innovation has concentrated mainly on various aspects of innovation chain separately. In this paper we tried to investigate the general effects of the whole elements of the innovation chain simultaneously. These elements are: R&D expenditures, physical capital formation, human capital and patent filling (residence and non-residence). We utilized multivariable time-series methods including cointegration and vector error correction model (VECM) to assess the long-run effects of innovation elements on total factor productivity in Iran. Results show that excluding the human capital variable, other elements of innovation chain have positive effects on TFP among them, residence and non-residence patent filling having the normalized long-run coefficients of 0.58 and 0.48 respectively, are the most important factors affecting TFP in Iran.

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Providing, maintaining and improving health of infants as a vulnerable group has a special place in health care. Due to the importance of this index in the United Nations development indices, we compared the socioeconomic determinants of infant mortality rate in Iran and MENA countries during 1980- 2010. The aims of this comparison was to determine major causes of inequalities in infant mortality rate in the region and also to determine why this index is very high and very low in different countries..

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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.