جستجوی مقالات مرتبط با کلیدواژه « transportation sector » در نشریات گروه « عمران »

The transportation sector includes activities that are widely effective in the processes of production distribution and consumption of goods and services. so, it plays a fundamental role in the economic growth of countries. However, investment in transportation infrastructure despite the positive effects, may not have maximum effects on growth in developing countries due to mismanagement and lack of proper strategy and plan in infrastructure development. As a result, considering the nature of investment in the transportation sectorm this sector and the growth of the national GDP from different dimensions and angles becomes more important. The current research has investigated this issue based on a "vector error correction model" and its estimation in the period from 1373 to 1399. the relationships of the variables used in this model can be specified in the form of three correlation relationships. These three relationships can be examined under the three relationships explaining real GDP, real exchange rate and real investment in the transportation sector, which respectively describe the behavior of the real sector of the economy, the behavior of the currency market and the behavior of investment in the transportation sector. According to the obtained results, the variable of investment in the transportation sector has an effect on the production variable in the long term, and the extent of this influence is such that each one percent increase in the real investment in the transportation sector can be 0.09 percent in growth Iran's economy will be effective.

Over the past decades, Iran’s economy has experienced a lot of Exchange rate fluctuations and the shocks to the value of national currency have been one of the major causes of inflation and its subgroups. This paper estimates the exchange rate pass through in transportation subgroup of CPI using econometric techniques on a sample spanning from March 2002 to February 2021. Results of our ARDL Model suggest that the ERPT in this subgroup is incomplete, with 52 percent of the exchange rate variations passing through to prices in long run. The speed of pass-through is low and it takes 25 months to converge to long run equilibrium. The results suggest that a 10 percent depreciation of the domestic currency relative to USD increase transportation sector prices by about 1 percent in the first month. Also, changes in the prices of a basket of goods and services at aggregate level (inflation rate) and increase of gas prices have a positive effect on inflation in transportation sector.

In recent years¡ carbon dioxide emissions have been a significant increase in the transport sector. Therefore¡ accurate modeling of carbon dioxide emissions is important to adopt a policy by managers and policy makers in the transport sector. This study using underlying trend concept and create a state- space model¡ Kalman filter algorithms which were estimated structural model of Environmental Kuznets Curve in the transport sector. The data used in this study is the annual time series over the period 1346-1392. The nature of the underlying trend is smooth¡ rising and non-linear. According to likelihood ratio statistic¡ most appropriate structure for hyper parameters¡ were local level model with drift model. The results indicate that the structural time series models¡ according to the implicit import (technology) inverted U relationship is confirmed for the transport sector. Also¡ The transport sector is on the descending curve. Variable coefficient of energy consumption in the transport sector is based on the theory and it is positive. According to the results of the assessment¡ to reduce carbon dioxide emissions¡ policy-makers and managers can plan to increase value added in transport and investing in new technologies.

Today, transportation is one of the most important sectors of the economy and because of effects short-run, medium term and long-run that have on economic main variables such as production, employment, prices and living cost index, have high position in country. Therefore the survey of this sector is necessary because of the effects of economic social on other economic sectors and distribution income.One of short run effects for transport development is that directly related to the increase or decrease in the cost of living through the transportation costs per household and indirectly through the impact on prices of other goods and services that affected transport prices. The medium term and long run effects include the effect of transport prices on consumption of alternative services such as communications and Changes in accounting principles and patterns of economic development respectively. Further more, based on the statistical center information of Iran, total value added in the transport sector at the end of 1388 based on 1376 real price is 41,805 billion rials that compared past year has 3.8 growths.

Regarding necessity the scientific and clear criteria utilization for evaluating environmental costs، this research estimated a stochastic output distance function by measuring the environmental pollution parameters via analyzing in the transportation sector، as well as collecting the survey inputs and outputs production data. According to the Pigou’s theory which says each polluter should pay the costs of its pollution، given the lack of appropriate analytical methods for environmental policymaking، in this paper we made an estimate of shadow prices for environmental pollutions resulting from fossil fuel consumption in transportation sector. Accordingly، the average shadow prices in the transportation sector during the period of time from 1357 to 1389 for pollutants including nitrogen oxides (NOx) is equal to -121469. 7 rials per ton-kilometer، sulfur dioxide (SO2) is equal to -131936. 9 rials per ton-kilometer and for carbon dioxide (CO2) is equal to -488. 4381 rials per ton-kilometer. These results suggested as a basic measure for planning to environmental policymakers to have a better knowledge of related economical-environmental effects of transportation sector and environmental costs.

Productivity improvement, considering resource scarcity and increased competition, is known, nowadays, as the best and most effective way of achieving growth. Since transportation is a very important and influential infrastructural component in the country's economy, the evaluation and improvement of its productivity is quite important. The purpose, in this paper, has been to calculate productivity in Iran transportation sector using Kalman Filter approach; the results for the potential production and production cycle have also been analyzed and compared using Hodric-Prescott (HP) and Boxter-King (BK) methods. To do so, first the unit root and random trend in the real GDP logarithm have been investigated and analyzed for the transportation sector during the period in question; results have shown that the real value-added logarithm variable of Iran transportation sector is first order integration I(I) and, therefore, the observed trend is one obtained from a random walk with drift. Next, based on the theoretical principles and experimental studies, the productivity model has been introduced and proposed for the transportation sector. The model equations can be rewritten, in the format of state-space models, as follows:ME:〖∆y〗_t=μ+y_(c,t)-y_(c,t-1)+ε_1t (1) TE:y_(c,t)=φ_1 y_(c,t-1)+φ_2 y_(c,t-2)+ε_(2t) (2) Model estimation results are shown in Table 1.Table 1. Estimated values of the model parametersParameter Estimation t-statisticµ 0.06 2.53φ1 0.74 10.52φ2 -0.8 -5.20σε1 0.24 9.86σε2 0.76 6.25AIC=-4.45 SBC=-4.23 Source: Research findingsAs shown in the above table, all the values estimated for the variables are meaningful at the critical level of 0.05. Also, the special roots of equation λ^2 〖-φ〗_1 〖λ-φ〗_2=0are: since C < 1, the business cycles in the real GDP logarithm of Iran transportation sector are stable; other parameters are meaningful too. Next, it is necessary to make sure of the model correctness regarding normality of the residues (model's error forecast) and lack of autocorrelation. To check the first, use has been made of Jarque-Bera statistic, and to check the second based on autocorrelation function (ACF) and partial autocorrelation function (PACF), it can be concluded, from the value found for the test statistic and its corresponding probability level, that the model lacks autocorrelation which is an indication of the model's goodness of fit. Test statistic results found from this model are 2.89 for the residues and 0.24 for its probability; therefore, the assumption of normal distribution at a certainty level of 5% cannot be rejected.Results have revealed that the fluctuation variance of the cycles produced by the Kalman-Filter method have been less than those by Hodric-Prescott and Boxter-King methods, but all have been similar in shape. The time series of the production total factor productivity for the time period of 1972-2007 in the transportation sector was estimated too. Fig.1 shows this sector's estimated productivity for the period 1971-2006. As shown, it has had fluctuations during that period; over time, the amplitude has declined in recent years which can be an indication of enhancement in the economic stability in this sector.Since improvement and increase in productivity in the transportation sector will cause more value added and hence more income will be distributed in this sector, and also considering the important role the transportation sector plays in the economic activities and in preparing the production's infrastructures, the productivity improvement in this sector will cause an increase in the GDP and, in fact, in the living standards in the country.

The increasing dependency of societies to energy due to the replacement of machines instead of human capital has made energy as an important factor of economic growth and it plays a considerable role in economic sectors operation. This paper examines the relationship between energy consumption and Growth Economic In the transportation sector of Iran for 1968-2008 using unit root tests, Granger causality. Also Hesiao method which is based on minimum final prediction error (FPE) has been used to determine the optimal lags of variables. The results of unit root tests show that both variables are stationary in levels. We find that energy consumption Granger is not causality Growth Economic also Growth Economic Granger is causality energy consumption In the transportation sector of Iran.