Journal of Quantitative Economics
Year:2012 | Volume:9 | Issue:1 (32)|Papers Count:8

Water as one of the most important human needs plays a vital role in everyday life. Therefore, awareness of the required amount of water demand is of particular importance to policy-making in line with demand management. In this study, a hybrid model (a combination of linear and non-linear models) has been designed to predict short-term urban water demand which matches with the climatic conditions and structure of Tehran and variables affecting the water consumption. With using the model, daily urban water demand for the next 10 days was predicted based by ARIMA, Artificial Neural Networks (ANN) and Wavelet Transform hybrid models. Then the forecasted values of mentioned models were evaluated by MAPE and R2 criteria in step-by-step and full 10 days predictions. Finally, wavelet transform hybrid model with low error (high prediction accuracy) was selected as an optimal model for predicting daily water demand of Tehran.

Considering the importance of the Okun’s law in economic policy making, the investigation of the relationship between unemployment and real production at provincial level lead to more efficient economic policies facing unemployment at provincial and national level. The aim of this paper is to estimate the Okun’s coefficients for different Iranian provinces and to determine provincial differences in relationship between GDP and unemployment rate. We estimated the Okun’s coefficients across the provinces using data over the period 2001-2008 and panel data model. The results showed that the Okun’s law holds for 10 provinces and does not hold for 12 provinces and is not robust for other provinces. Moreover, using Wald test, the results also showed that the Okun’s coefficients are statistically different among different provinces.

The easy flow of capital in international markets has led to dynamic relationship between exchange rate and capital in two ways: where any change in the determining parameters of one affects the other. The present study attempts to investigate the relationship between the uncertainty of the exchange rate of the dollar to the rial and the stock price index of the Tehran stock market as well as the dynamic reaction of each in relation to the other. The findings showed the existent of least one long run equilibrium relationship between the uncertainty of the exchange rate and the uncertainty of the stock price index of the Tehran stock market. These results also showed that neither of the uncertainty lags between zero and ten affected the stock price index. Thus rejection of the hypothesis indicates that there exists no causality relationship from the exchange rate to uncertainty in the stock price index for most of the lag duratign. Therefore, there exists a one-way causality relationship from the uncertainty of the exchange rate to the uncertainty in the stock price index.

The role of international trade on human development is important for economists. Some studies emphasize that there is a positive link between trade and economic development, while others believe that trade has a negative impact on national sovereignty and indigenous culture of countries. In this paper, we attempt to address this argument by examining the impact of international trade on countries’ social developments as measured by the Human Development Index. We have utilized a System Generalized Method of Moments procedure in a panel data framework, using the data for the 16 countries in the period of 1975- 2009. The results showed that increases in trade are positively associated with increases in the human development, which eventually leads to the social welfare of the society.

In view of historical experiences and theorical studies, economic structural changes can effect economic growth through improving utilization of resources along with the main factors, i.e.capital and labour. This paper studies the role of economic structural changes using the share of manufacturing sector in GDP and in total export, as well as the ratio of labour productivity in manufacturing sector to agriculture sector. The results showed that the share of manufacturing sector in GDP and in total export, have negative affects on economic growth. These results are consistent with of historical experiments in industrialized and new industrialized countries. The results also showed that the ratio of labour productivity in manufacturing sector to agriculture sector has a positive affect on economic growth in Iran.

Reducing government budget dependency on oil revenues is one of the Iranian twenty- year vision (Iran vision 1404) document goals and also fourth and fifth economic-social development plan targets in Iran. Therefore, to reduce government budget dependency on oil, the best way is to increase tax revenues as the best alternative. In this study, the Bellman equations were used to determine the optimal path for tax revenues in order to reduce the budget dependency. The main objectives the study were to obtain the optimal tax path for government public expenditure in the final year of Iran vision 1404, and also to finance government current expenditure by tax revenues in the last year of fifth economic social development plan.

This paper examines the relationship between productivity growth and oil growth during the period of 1981-2007. It first, reviews the theoretical and empirical a literature and measures productivity growth in Iranian oil sector. The paper also examines the causal link between productivity growth and oil growth in Iran using unit root and co- integration techniques within a bi-Variate Vector Auto– Regressive (bVAR) and Vector Error Correction (VEC) framework. The results revealed a positive relationship between productivity growth and oil growth in Iran. The causation is directed from productivity growth toward oil growth.