Economics Research

Abstract Due to uncertainty in economic growth theories, existence of various proxies for effective factors on economic growth, and lack of indication of the most appropriate econometric model for investigating effective variables on economic growth, the empirical growth regressions have always faced uncertainty. To investigate this phenomenon, we should move from the classical econometrics towards the approaches which can appropriately deal with uncertainty. One of these approaches is the !Bayesian Averaging of Classical Estimates Approach" which has been used in this article to evaluate the uncertainty of the effects of trade openness on economic growth in developing countries (52 countries) during 1970 and 2006. The research findings indicate that the !Composite Trade Intensity" which is considered as a suitable alternative for trade openness, has a positive and definite effect on economic growth of these countries in the long run. Furthermore, it is revealed that other criteria such as !Unweighted Averages of Tariff Rates", !Terms of Trade Growth" and !Sachs & Warner openness indicator" (1995) # as  proxies for trade openness # do not have definite and determining effects on economic growth of these countries in the long run.

Abstract Efficiency, optimal allocation of sources depends on competitive performance of markets. To establish competitive markets, maintain and increase efficiency, it is necessary to exist different issues including complete definition of legal ownership, reduction of conventional and exchange costs, facilitating the flow of information among producers and consumers in the markets and also existence of facilitator rules concerning competition and anti-monopoly. In this research, we have collected the statistics of big industrial working places in 2007 and computed the concentration and monopoly indexes for 130 industries by using Hrefindhal – Hirshman and share of better firms indexes. In addition, we have evaluated the role of private and public companies in increasing and reducing the monopoly, and the effective factors in creating & sustaining of monopolies. Results from the research indicates the considerable concentration in Iran’s including in public & private sectors. The most important reason to establish monopolies in the country, either in public or private sectors, is creating input obstacles through laws and regulations.