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The world is changing at a rapid pace and our viewpoint too. Moreover, the impact of government policy on social and economic growth is changing at the same pace. Many researchers have attempted to estimate the impact of government expenditures on economic growth. In this regard, they have used either a particular statistical model or Ram’s model (1986) employing a production function which criticized because of statistical limitations. The purpose of this article is to introduce an alternative theoretical framework based on the conventional demand theory applied by Bairam (1990). The annual time series data from 1974 to 2005 is employed to examine the effect of government size on economic growth in Iran. The empirical findings indicate that the government expenditures have a positive effect on economic growth which is consistent with the theory used in this paper and also it is in harmony with the empirical results of the similar studies.

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This paper develops a New Keynesian dynamic stochastic general equilibrium (DSDE) model to study Iran's economy. The model considers the dependence of Iran's economy to oil exports. Oil sector and oil export revenues have been modeled as a separate sector and one of the government budget resources, respectively. In this model, like in other New Keynesian DSGE models, firms face nominal rigidities and the intermediate-good sector is monopolistically competitive. Four shocks (productivity, oil revenues, money growth rate and government expenditure) have been introduced as the sources of volatility. The findings show that business cycle moments generated by the model and those of actual statistics from the economy are closely related. The model produces more volatile private investment and less volatile private consumption than non-oil output. Impulse response functions of shocks show that non-oil output increases in response to productivity, oil revenues, money growth rate and government expenditure shocks. Although non-oil output increases in response to government expenditures shocks, crowding- out effect of these expenditures causes output to decrease after some periods.

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Regarding the differences among firms on financial position and access to various financial resources, the selection of a proper variable, which represents actual cost of capital of a firm, is of great importance in explaining the firms demand for money.  In order to improve the estimation of interest rate elasticity of demand for money by manufacturing firms, this paper computes the cost of capital for each firm. Using firm level panel data for 161 manufacturing companies listed in Tehran Stock Exchange, the demand for money is estimated over the period 2000 to 2010. It is found that (a) the firms in which the cost of capital is higher, have low real balances; (b) the average cost of capital and its variations implies that the weight of cost of capital should be reexamined by monetary authority; and (c) the sensitivity of demand for money to fluctuations in wage  is more than to interest rate.

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Exchange rate is the key variable in each economy. This paper tries to examine the effects of volatilities in exchange rate market on selected macroeconomic variables in Iran, and to present some strategic recommendations. Inspiring by Danmola method, this paper uses the variance decomposition and impulse response function based on Cholesky decomposition of Vector-autoregressive method. The findings show that real exchange rate volatility has the most effect on profit rate of the short-run deposits during 2001:Q1-2012:Q4. Following profit rate of short-run deposits, the highest variation in inflation rate is explained by real exchange rate volatility.  The economic growth is affected positively by exchange rate volatility (EEV) in both short- and long-run, but it is influenced negatively by EEV in the midterm.  On the other hand, trade balance is deteriorated by shocks in real exchange rate with short lags. Our findings are compatible with those of similar studies among developing countries.