---

The magnitude of economic growth depends on the growth and investment in key economic sectors. Thus, one important goal of policy makers and economic planners in any society is to identify key economic sectors. This paper aims at identifying these sectors in Iranian economy using stochastic input-output analysis. Stochastic analysis is used to investigate how the inherent imprecision affects the concomitant key sector analysis in case of utilizing aggregated data. The analysis is based on Iranian input-output table for the year 2001, using distance estimation and Monte Carlo simulation. Results of the non-stochastic approach indicate that among 25 economic sectors in aggregated input-output table, six sector-groups are the key sectors while, in non-aggregated input-output table with 99 sectors, 13 sector-groups can be identified as key sectors. Finally the suggestion is that to identify key economic sectors the non-aggregated input-output table should be used.

---

This study aims to evaluate the status of Iranian gas industry and to formulate appropriate policies in order to attain the objectives of Iran’s Vision 2025. A dynamic model including exploration, production, consumption and demand sub-systems is designed based on the system dynamics approach and is simulated for the period 2010-2025. In this model, factors affecting natural gas exploration, demand and consumption as well as production, export and import of all other fuels in energy supply are identified and their dynamic interactions are investigated. The results of solving the basic model indicated that except for a 75 % share of gas consumption, none of Vision’s objectives would be attained, if current policies were followed. Accordingly, new policies are formulated and included in the model in the form of some scenarios. The results of simulating such scenarios suggest that other than coordinating the subdivisions of gas industry, production and exploration rates should be increased and significant technological exploration and production advances should be made in order to attain the objectives considered in the gas industry. Furthermore, clean energies such as water, wind and solar resources should be utilized increasingly in order to supply a part of domestic consumption. The results of model validation tests indicate the validity of the model as acceptable.