فصلنامه پژوهش های اقتصادی ایران
پیاپی 68 (پاییز 1395)

In physical input-output tables (PIOTS), the flows of products, instead of being expressed in monetary terms, are represented by physical measures (weight, time). Furthermore, these tables along with the traditional inter-industry transactions of monetary tables (MIOT), contain the flows between the economy and the natural environment. Thus, it is assumed that the use of natural resources by the economic system and return of the waste to the environment should be included in the process because the economy "depletes the environment beyond its regenerative capacity and pollutes it beyond its absorptive capacity." Traditional economics considers the economy as an isolated or closed system which is "a circular flow of exchange between firms and households in which neither matter nor energy enters or exits." It has no relation with its environment, while in fact it is an open subsystem of the earth's ecosystem. This standard vision is definitely useful for analyzing exchange, price formation, and income determination, but quite useless for studying the relation of the economy to the environment. The rationale behind material input-output tables, is based on the above observations. In this article after briefly examining this line of reasoning, the experience of two forerunning countries in the construction of material supply, use and input-output tables - Germany and Denmark - is presented. In explaining the subject, we have also benefited from several UN publications on System of Environmental Economic Accounting. In countries like Iran, with fragile environmental resources, this type of data and analysis, seems to be very promising.

In the combined domain of economy and environment, the process of production of goods and services contain three intertwined cycles: primary cycle (natural resources), secondary cycle (intermediate and final goods and services) and the end cycle (overflows, wastes or waste disposal to the environment). The Monetary Input - Output Table (MIOT) organizes only the visible production process of goods and services and data are in terms of price - quantity simultaneously. Prices in MIOT are ordinary, homogeneous and positive for an accounting period. The other two cycles are exogenous with zero prices. As they are outside of the accounting system, we call them invisible cycles. In order to remove this limitation, the Physical Input - Output Table (PIOT) has been designed by some of European countries at the end of 20th Century. This table considers simultaneously all the three cycles in the visible manner. The data are of physical in nature (in tons) without prices and mass unit instead of value unit is used. The design of the PIOT parallel to the MIOT is triggered by two major questions among the analysts in the 21th Century. Firstly, which one of the two tables can reveal the interworen physical nature of economic-environment and sustainable development? Secondly, analogous to the basic theory of MIOT, is it possible to model the PIOT? With respect to the questions posed, the existing literature in the past fifteen years are classified into three groups: The empirical evidences of the first group show that as compared to the MIOT, the PIOT has more potentiality in revealing the physical nature of the combined economic-environment in relation to the sustainable development. This finding is questioned by the second group. The third group has cast doubts to the pros and cons of the treatment of waste as input or output and suggest that the differences are not in the treatment of waste as an input or output. According to them, the root of the differences lies in the nature and the function of prices in both the MIOT and PIOT. The third group overshadows two points: One is that they have not identified the use of the different types of prices like; implicit, unit and homogeneous or implicit matrix prices in converting PIOT to MIOT. Second is that they have not discussed the issue of the balancing of the converted PIOT to MIOT. Based on the 1990 PIOT and MIOT of Germany, we demonstrate first of all that the double deflation method cannot convert the PIOT into MIOT and secondly, use of the implicit matrix price under the assumption of the zero price of waste can convert the PIOT into the MIOT.

Iran is located on fault lines and due to abundant seismicity as well as being positioned on one of the world's seismic belts Lpa, it is very vulnerable to earthquakes. In addition, in spite of having one percent of the world's population, Iran suffers from more than six percent of all casualties from natural disasters in the world. Many major cities including Tehran are located on active faults. In the event of a potential earthquake Tehran's general urban weakness, high population density, and poor dispersion in neighborhoods can cause significant casualties and structural damage. Due to high level of trade with other provinces, the extent of damage would not be limited to Tehran and can cause considerable damage to the economy at a national scale. The main goal of this paper is to predict the regional economic loss from earthquake in Tehran and the rest of the country using a two-region input-output model. The main source of the data is a two-regional input-output table, which is constructed from 2011 national input-output table (Parliament Research Center) and regional accounts (Statistical Center of Iran), using FLQ non-survey based technique. The sectoral vulnerability under the five scenarios: none, little, moderate, major, and extensive are borrowed from Rahimi (2012). The results showed the economic impact of earthquake in Tehran on its GDP would be 81% in none, and up to 103% in the extensive scenario, while for rest of the country it would be 24% to 30% of national GDP.

Since the introduction of supply-use input-output model by the United Nations in its 1968 SNA, there has been a controversy on choosing the most appropriate technology assumption for estimating symmetric product by product input-output table. These arguments have focused on two technology assumptions; the product technology assumption (PTA) and the activity technology assumption (ATA). The PTA states that each product has a unique input structure that is independent of producing industry. In contrast, the ATA is defined as each activity has its own specific way of production, irrespective of its product mix. Each assumption has its own advantages and disadvantages. Because of ATA’s inconsistency with some fundamental economic theories, “Product Technology” assumption is more widely applied for calculating symmetric product-by-product input-output table. In this paper, we show that only PTA fulfills the four desirable properties (material balance, financial balance, scale invariance and price invariance) which are introduced by Jansen and ten Raa (1990) but ATA fulfils only one of them. This result can be used by compliers and users in choosing the appropriate economic assumptions for deriving symmetric input-output tables.

Considering its biological situation, each country has a specific carrying capacities to absorb pollutants. Increased production, population, and direct and indirect fossil energy consumption have increased emissions such as carbon dioxide, resulting in destructive effects on the environment such as imbalanced greenhouse gases, global warming, climate changes, and endangering of humans’ and other creatures’ lives. The extent and dimension of the mentioned effects can vary depending on the consumption modus and technique practiced by households and industries. Ecological carbon footprint is a criterion to measure the humans’ impact on carbon emissions. In an attempt to measure the carbon footprint of households, this research seeks to answer the following questions: How much is the carbon footprint of urban and rural household deciles? What deciles create higher carbon footprints? What is the share of households in the country’s total carbon footprint? How big is the carbon footprint per capita in each decile? For this purpose, the Social Accounting Matrix of the year 2011 is used. The empirical results indicate that in 2011, the total net direct and indirect carbon footprint in Iran was 517 million tons, in which the household consumption accounts for 64% and the remaining 36% belongs to the government’s final consumption, export and others. Moreover, carbon footprint of urban households is more than the rural ones and it is elevated in higher income deciles. Carbon footprint of the tenth urban decile is 11 times greater than the first one. For rural deciles, this ratio is 9. Furthermore, carbon footprint of the tenth urban decile is 4 times greater than that of the tenth rural one. An Iranian’s household carbon footprint per capita was found to be about 4429 kg in 2012. Carbon foot print per capita in the first urban decile, the tenth urban decile, first rural decile, and the tenth rural decile is 1,124, 17,134, 965 and 9,803 kg, respectively. The results indicate that people with higher incomes have a greater carbon footprint.

The most well-known application of the supply and use tables is the calculation of a variety of symmetric tables with different technological assumptions. From the 1960s to the late 2000s, only symmetric industry by industry tables under fixed sale commodity assumption, could be used as the basis of updating. However, a symmetric table cannot provide the simultaneous analysis of product and activity and, therefore, cannot be applied in any fields of economy. Since the late 2000s, the input-output analysts have developed various methods in order to directly use the supply and use tables as the basis of updating instead of updating the symmetric tables. Despite more than three decades of experience of compilation of the supply and use tables in Iran, statistical institutions still use the symmetric tables as the basis of updating. The present paper aims to quantitatively study and compare conventional methods of updating the supply and use tables with the view to answer the following question: Which of the reviewed methods best suits the available statistics in Iran and can be applied for the updating the supply and use tables? The results show that, among the methods under consideration, the SUT_RAS method is more consistent with the nature of data and statistics in Iran.