Index No Statistics
Standardized description of index numbers for application in generic index computation software modules 1
Photis Stavropoulos1, Georges Pongas2, Spyros Liapis1, George
Petrakos1, Tonia Ieromnimon1
Agilis S.A. Statistics and Informatics, e-mail: Photis.Stavropoulos@agilis-sa.gr,
Spyros.Liapis@agilis-sa.gr, George.Petrakos@agilis-sa.gr,
Tonia.Ieromnimon@agilis-sa.gr
2
EUROSTAT, e-mail: Georges.Pongas@ec.europa.eu
Abstract
The aim of this paper is to present a scheme for the description of index numbers in a standardized manner and to show how this scheme was realized in a generic software module for the computation of index numbers. Index number theory provides statisticians with a palette of formulae and computational operations (chaining, aggregation, etc.) to build index calculation since there is no unique way of measuring an index number. The proposed scheme has been developed in such a way so as to allow the user to define the characteristics/parameters of the index: index type, base period, reference period of the weights, periodicity of input data and of the index, dissemination dimensions, mode of aggregation, etc. These characteristics may be viewed as ‘process metadata’, which can guide the computation of an index. The tool allows the different mix of index types and computational operations. It covers computational tasks common in several domains where indices are used. Moreover it can be expanded to accommodate new operations, with little extra programming, that apply to particular domains and are needed for the computational of additional indices. Further work is envisaged in making the tool even more generic to accommodate more computations and be applicable to different domains.
Keywords: Index numbers, Process metadata, Building block
1. Introduction
Index numbers are widely used in Official statistics to convey information about the relative size of a variable (price, quantity, etc.) between different points in time or between different
Photis Stavropoulos1, Georges Pongas2, Spyros Liapis1, George
Petrakos1, Tonia Ieromnimon1
Agilis S.A. Statistics and Informatics, e-mail: Photis.Stavropoulos@agilis-sa.gr,
Spyros.Liapis@agilis-sa.gr, George.Petrakos@agilis-sa.gr,
Tonia.Ieromnimon@agilis-sa.gr
2
EUROSTAT, e-mail: Georges.Pongas@ec.europa.eu
Abstract
The aim of this paper is to present a scheme for the description of index numbers in a standardized manner and to show how this scheme was realized in a generic software module for the computation of index numbers. Index number theory provides statisticians with a palette of formulae and computational operations (chaining, aggregation, etc.) to build index calculation since there is no unique way of measuring an index number. The proposed scheme has been developed in such a way so as to allow the user to define the characteristics/parameters of the index: index type, base period, reference period of the weights, periodicity of input data and of the index, dissemination dimensions, mode of aggregation, etc. These characteristics may be viewed as ‘process metadata’, which can guide the computation of an index. The tool allows the different mix of index types and computational operations. It covers computational tasks common in several domains where indices are used. Moreover it can be expanded to accommodate new operations, with little extra programming, that apply to particular domains and are needed for the computational of additional indices. Further work is envisaged in making the tool even more generic to accommodate more computations and be applicable to different domains.
Keywords: Index numbers, Process metadata, Building block
1. Introduction
Index numbers are widely used in Official statistics to convey information about the relative size of a variable (price, quantity, etc.) between different points in time or between different
References: Eurostat - OECD, 2006. Methodological manual on purchasing power parities. Fisher, I. (1967) Making of Index Numbers, Augustus M Kelley Pubs, 3rd Edition. Forsyth, F.G., R.F. Fowler (1981). The Theory and Practice of Chain Price Index Numbers, Journal of the Royal Statistical Society, Series A, Vol. 144, No. 1, pp. 224–46. International Monetary Fund, 2001. Quarterly National Accounts Manual. International Labour Organisation, 2004. Consumer Price Index Manual: Theory and Practice.