Editorial

Authors

• afsane sherkat ¹
• Mohammad Jelodari Mamaghani ²
• Ali Asghar Banouei ³
• Ashkan Mokhtary Asl Shouti ⁴
• Sonia Sabzalizad Honarvar ⁵

¹ PhD student in Economic Sciences, AllamehTabatabai University

² Professor, Faculty of Mathematics & Computer Sciences, Allameh Tabataba`i University

³ Professor, Faculty of Economics, Allameh Tabataba`i University

⁴ Graduated Student in Planning and Development Economics, Faculty of Economics

⁵ Ph.D Student, Faculty of Social Science & Economics, Al-Zahra University

Abstract

In this paper, we have used four conventional, Adjusted, Generalized, and Adjusted Generalized RAS methods to update input-output Coefficients (IOC). Conventional and Adjusted RAS methods can only update positive and zero cells and are not sensitive to the existing negative cells like net exports and/or net taxes in Input-Output Tables (IOTs). To solve this drawback, analysts have proposed Generalized RAS (GRAS). This method can update positive, zero and negative cells. From the application view point, this method has two limitations: First, it is more focused on numerical examples rather than real IOTs. Second, extending the GRAS to AGRAS has not been attempted yet. The above limitations will lead us to pose the following questions: is it possible to extend Generalized RAS to Adjusted Generalized RAS? And which method has more statistical errors? For this purpose, we have used the two aggregated survey based IOTs of Iran for the years 1996 and 2001. Our findings show that it is possible to extend GRAS to AGRAS. Whit respect to the measurement of statistical errors, the following results have been obtained:  first, the statistical errors of GRAS is lower than Conventional and ARAS, and the second statistical errors of AGRAS are much lower than corresponding figures in Conventional, ARAS and GRAS.

Keywords

• Input-Output Table
• Conventional RAS Method
• Generalized RAS Method
• Adjusted Generalized RAS Method
• Positive and Negative Elements