Zahra Moshfegh; Golrooz Ramezandeh Valis; Afsaneh Sherkat; Mohadeseh Soleimani; Ali Asghar Banouei
Volume 19, Issue 58 , April 2014, , Pages 117-152
Abstract
There are several methods of updating input-output coefficient matrix in last six decades, but there are still issues about RAS and adjusted RAS methods which have been focus of input-output analysts in recent years. One challenging issue is the relationship between more exogenous, superior or additional ...
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There are several methods of updating input-output coefficient matrix in last six decades, but there are still issues about RAS and adjusted RAS methods which have been focus of input-output analysts in recent years. One challenging issue is the relationship between more exogenous, superior or additional information of target year in adjusted RAS method and its statistical reduction error relative to conventional RAS method in updating the input-output coefficient matrix. Some analysts observe the positive relationship, whereas others by focusing on the nature and criteria of exogenous information opine that using more exogenous information in the adjusted RAS will not necessarily reduce the statistical errors compared to conventional RAS method. The existing evidence in Iran is around the findings of the positive relationship which has in fact lead to the common belief between compilers and also users of table in Iran. In this article we attempt to examine this issue by means of two symmetric input-output tables of the years 1996 & 2001 by posing two main questions. The first question: Is there any relationship between more exogenous information in adjusted RAS method compared to conventional RAS method in reducing statistical errors? Second question: Do the nature and criteria of more exogenous information, irrespective of more or less cells; have an influence on increase or reduction of statistical errors in updating coefficients? Our findings do not support the existing common belief among the compilers and users of Input-Output Table in Iran and reveal the followings: 1- The adjusted RAS method, in some of exogenous information, is not preferable to conventional RAS method. 2: Measurement of credibility of updated coefficients depends on choice of the nature and criteria of exogenous information, and 3: Using more exogenous information of the target year would not necessarily lead to decrease of statistical errors in the updated coefficients.
Sonia Sabzalizad Honarvar; Mohammad Jelodari Mamaghani; Aliasghar Banouei; Afsaneh Sherkat; Ashkan Mokhtary Asl Shouti
Volume 18, Issue 57 , February 2014, , Pages 69-84
Abstract
During thepast six decades, the analysts of the input – output economics(IOE) have used two approaches of input – output coefficient matrix(IOCM) and intermediate transactions matrix(ITM), both of which are based on iteration algorithms, in updating input – output tables(IOTs). The ...
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During thepast six decades, the analysts of the input – output economics(IOE) have used two approaches of input – output coefficient matrix(IOCM) and intermediate transactions matrix(ITM), both of which are based on iteration algorithms, in updating input – output tables(IOTs). The former is theoretically based on the production function and is more popular as compared with the latter which is only in terms of accounting. The challenging issue for the analysts of IOE is similar or different results of the two approaches. A group insists on different results, whereas, the observations of another group suggest that the results are equivalent. Neither of the mentioned groups consider factors such as aggregation and convergence speed with respect to the number of iterations in algorithms of the two approaches. The main focus of this article is to investigate the theoretical and empirical aspects of factors, using two survey-based symmetric IOTs of Iran for the years 1996 and 2001. With respect to the above factors, the 3 sectors, 7 sectors, 15 sectors and 21 sectors are considered. This article concludes two overall findings: a 1-statistical error in the two approaches exits but insignificant. 2-The convergence speed with lower number of iterations in the IOCM approach is higher than that of the second approach.
