Abstract:
By shouldering the burden of a big chunk of global production, and giving Shelter to half of the world’s population, currently cities play an important role in national economies. Benefits of agglomeration in cities have played a major role in the process of economic development of different countries, however, the expansion of urbanization has produced some problems including environmental and noise pollutions and traffic problems. Therefore many of the Metropolitan residents blame the population growth for the problems they face while urban governors have to find an answer to the question that if there is an optimum size for their cities, what is that size? This essay reflects on the optimal and sustainable size of the metropolitans in Iran and gives separate estimation for each. Due to scarcity of statistical information this article includes five metropolitans of Tehran, Isfahan, Mashhad, Shiraz and Ahvaz, within the time span of 1999 to 2012. This survey is based on the estimation of surplus function including the pollution externalities. The results show that Tehran is overpopulated to the excess of 71 percent of its optimum size, and also it has exceeded its sustainable size by five percent. Also other four metropolitans of Isfahan, Mashhad, Shiraz and Ahvaz have exceeded their optimal size but they still are in their relevant sustainable limits.
Machine summary:
"Optimal and Sustainable City Size by Estimating Surplus Function for Metropolitans of Iran Naser Yarmohammadian∗ Nemat Akbari** Ali Asgary*** Naser Movahedinia**** Abstract: By shouldering the burden of a big chunk of global production, and giving Shelter to half of the world’s population, currently cities play an important role in national economies.
Prior to Alanso (1971) most of studies saw the optimum size of the cities in relations to the minimum cost of public goods, and they believed the best level of population where the expenditure of local governance in minimum.
According to this proposal Henry George theorem state when a city has an optimal population size, the aggregate urban differential land rents can cover the costs of pure public goods (Fu, 2004).
So total benefit function is as follow: به تصویر صفحه رجوع شود According to the local economic model, total expenditure was a function of price level, rent, Pm, utility level in the city, u, population, previous level of pollution, En, and the tax rate, t.
Table 3: Optimal size and Surplus ratio of metropolises به تصویر صفحه رجوع شود As it was mentioned before, although from the central planning point of view, an efficient situation happens at the optimum level of cities, but it is not necessarily sustainable because still the positive balance for the net profits for the residents attracts more people to the city."