The main aggregates in the Supply and Use and Input-Output Tables for Ireland 2021 are consistent with the data in the Annual National Accounts 2023 (ANA 2023). All publications follow the European System of Accounts methodology (ESA 2010). Detailed information on the Supply and Use compilations is found in the Background Notes chapter of that release.
The tables display details of the economy in terms of 60 industry groups and 60 product groups. The industry classification used is the two-digit level of the NACE Rev. 2 referred to as the A88 coding of industry activities. The product classification used is the equivalent CPA Rev. 2.1 grouping referred to as the P88. The tables are initially constructed using 88 industry and 88 product groups and are then condensed for confidentiality and quality purposes.
The basis of the methodology used is described in the Eurostat Manual of Supply, Use and Input-Output Tables and in the UN Handbook of Input-Output Table Compilation and Analysis.
There are five Intermediate Tables (Tables 1.2 to 1.6) which are calculated using the Supply Table and the Use Table, they are then used to create the Input-Output tables.
The Supply Table is measured in basic prices and transformed to purchasers’ prices in the Supply and Use process by adding margins and taxes and subsidies. The Use Table is measured in purchasers' prices, so in order to transform the Use Table into basic prices, the margins and taxes less subsidies are removed across industries and components. This is done by creating a Use Table based off of the three columns (margins, taxes and subsidies) available in the Supply Table. These tables are available in the release as Use Table for trade margins (Table 1.5) and Use Table for taxes less subsidies on products (Table 1.6). These tables are subtracted from the Use Table at purchasers’ prices to create a Use Table at basic prices (Table 1.2).
There is consistency between the Use Table for trade margins and the Trade Margins column available in the Supply Table. Looking at the products of Agriculture, Forestry and Fishing, the Trade Margins value in the Supply Table is €1,810m, this is equal to the total uses in the Use Table for trade margins, which is the sum of the product row. This is consistent across all product codes. Likewise, there is consistency between the Use Table for taxes less subsidies and the Taxes and Subsidies columns in the Supply Table. Again, looking at products of Agriculture, Forestry and Fishing in the Supply Table, the Taxes value is €80m and the Subsidies value is -€106m, giving a Taxes less Subsidies value of -€26m. This is equal to the total uses value in the Use Table for taxes less subsidies, which is the sum of the product row.
To create domestic multipliers a domestic Input-Output Table is needed. This requires the Use Table to be disaggregated into domestic inputs (uses) and imported inputs (uses). The Use Table for imports is created first. The starting point for this is the Imports column which is available in the Supply Table. The sum of the product row for Agriculture, Forestry and Fishing in the Use Table for imports is €1,863m, equal to the Import figure for the same product code in the Supply Table. The Use Table for imports explains how imports are being used throughout the economy. The Use Table for domestic inputs is calculated from the residual of the Use Table at basic prices and the Use Table for imports.
Consistent analysis and adjustments are required throughout the process of calculating these intermediate tables. For example, domestic inputs are calculated as the residual of total use minus imported use and this can result in negative cells, but use cannot be negative. These negative cells need to be examined and understood in order for adjustments to be made to ensure all cells are positive, while retaining column/row consistency throughout.
There are three IO Tables; one for each of the Use at basic prices tables, a Totals Table, a Domestic IO Table, which refers to the consumption of domestically produced products and an Imports IO Table, which refers to the consumption of imported products.
The structure of the IO tables is similar to the structure of the Use table but differ in the following ways:
The conversion of the asymmetric Use Table to the symmetric IO Table is underpinned by certain assumptions in regards to the production of secondary products; the off diagonal elements in the domestic Supply Table. IO Tables can be either industry by industry or product by product based, and the assumption differs slightly depending. In this instance the Product Technology Assumption is used in the conversion (the Industry Technology Assumption would be used in the industry by industry case); which assumes that a product will have the same input structure regardless of what industry produces it. It also assumes all industries will respond accordingly to meet the change in demand, and that there will be no price adjustments or supply constraints during the production.
The IO Tables are calculated as Xp = U⋅S-1⋅q where:
The Domestic IO Table is used to calculate Coefficients of domestic product flows and the Leontief Inverse of domestic flows with multipliers for other inputs. The Table of Coefficients explains the direct input requirements per unit of output, while the Leontief Inverse shows the inputs required per unit of final demand.
The Coefficients Table is calculated by dividing each cell of the Domestic IO Table by its column total. The column total is the total inputs/outputs value. In the new Coefficients Table each column sums to 1. In Table 1.9 (Domestic IO Table), for product*product Agriculture, Forestry and Fishing there is a value of €1,760m. Total inputs/outputs for this product category is €11,493m. The corresponding figure in Table 1.12 (Coefficients Table) is 0.15313 (€1,760m/€11,493m).
The Leontief Inverse is calculated as L = (I – A)-1 where:
The Leontief Inverse Table can be interpreted as follows, continuing with the Agriculture, Forestry and Fishing example in the Key Findings chapter. Each €1 of final demand for domestic output of these products will require:
and so on down the column, which when summed together gives the Output multiplier. As mentioned, the Output multiplier shows how much direct and indirect output is required, across all domestic products per €1 of final demand for the products named at the top of the column. Note that this approach includes duplication of output. This is due to outputs measured as gross, rather than net value; duplication occurs where one product is involved in the production of another product and the cost being absorbed in the final value of that product, rather than adding to the final value.
The lower portion of the Leontief Inverse Table shows the direct plus indirect effect on other inputs per €1 final demand. In each column the sum of the coefficients of imports, taxes less subsidies, compensation of employees, consumption of fixed capital and net operating surplus add to 1. They show, after all the cycles of production are completed, how the additional unit of final demand was spread over these categories. There is no duplication in these coefficients.
The following conventions are used throughout the tables of this publication:
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